Dear Label_Name,

Greetings! I hope you are well.

I am writing on behalf of an international publishing house, Science and Education Publishing, USA (http://www.sciepub.com).

Science and Education Publishing (SciEP) is a multidisciplinary open access publisher of Journals covering the fields of Science, Technology and Medicine. All SciEP publications are subject to high-quality peer review, editorial and production processes and are freely available online.

Welcome to the April, 2013 edition of SciEP newsletter, providing monthly summaries of articles on science & education related topics of interest to scientist and professionals. The mission of our journals is to provide an open access forum for publishing new findings on issues pertinent to scientific and academic field. We also invite you to submit original research papers, review articles, short reports, or case studies are considered for publication in our Multidisciplinary Journals.

American Journal of Public Health Research
DOI: 10.12691/ajphr-1-1-3

The Implementation of a Tele-Homecare System with Service Oriented Architecture and HL7 Message Transmission Standard
Ching-Sung Wang

American Journal of Medical and Biological Research
DOI: 10.12691/ajmbr-1-1-2

The Influence of Ethanol on Pyruvate Kinases Activity in Vivo, in Vitro, in Silico
Lelevich Sergey Vladimirovich, Khrustalev Vladislav Victorovich, Barkovsky Eugene Victorovich, Shedogubova Tatyana Aleksandrovna

American Journal of Medical Sciences and Medicine
DOI: 10.12691/ajmsm-1-1-1

Clinical and Histological Features in Wegener Granulomatosis
Li Cavoli Gioacchino, Passantino Rita, Bono Luisa, Tortorici Calogera, Ferrantelli Angelo, Giammarresi Carlo, Rotolo Ugo

American Journal of Infectious Diseases and Microbiology
DOI: 10.12691/ajidm-1-1-2

The Curse of Lymphatic Filariasis: Would the Continual Use of Diethylcarbamazine Eliminate this Scourge in Papua New Guinea?
Anne Lanham, Lillian Mwanri

We have released issues of some journals on February 2013.
American Journal of Public Health Research
American Journal of Medical Sciences and Medicine
American Journal of Medical and Biological Research
American Journal of Pharmacological Sciences
American Journal of Clinical Medicine Research
American Journal of Nursing Research
American Journal of Cancer Prevention
American Journal of Medicine Studies
American Journal of Infectious Diseases and Microbiology
American Journal of Cardiovascular Disease Research
American Journal of Biomedical Research
American Journal of Mechanical Engineering
American Journal of Microbiological Research
Journal of Preventive Medicine
American Journal of Food and Nutrition
American Journal of Hypertension Research
American Journal of Sports Science and Medicine
Journal of Cancer Research and Treatment
American Journal of Zoological Research
Journal of Biomedical Engineering and Technology
American Journal of Microbiological Research
Biomedical Science and Engineering

We are pleased to announce that submissions are now being accepted for peer review for all the journals across all our subject areas in SciEP.

Please submit your manuscript via our online submission system:
http://www.sciepub.com/author/signin

To unsubscribe from our mailing list, please click on the following link: unsubscribe

I am looking forward to hearing from you.

Kind regards,

David Rain
Email:join@sciepub.com
Science and Education Publishing (http://www.sciepub.com)

Absence of CHEK2 1100delC, R145W and I157T Mutations in Breast Cancer in a Moroccan Population

Amal ElAmrani, Khalid Moumad, Mohammed Attaleb, Mustapha Benhassou, Asta Försti, Moulay Mustapha Ennaji, Mohammed El Mzibri, Meriem Khyatti*

Oncovirology Laboratory, Institut Pasteur du Maroc, Casablanca, Morocco

Abstract: Mutations in the BRCA1 and BRCA2 genes confer a high risk of breast cancer (BC), although they account for only a small fraction of BC susceptibility. Rare mutations in genes conferring moderate risk may contribute to BC risk. Previous studies have shown that mutations in the CHEK2 gene, which encodes for an upstream regulator of BRCA1, may cause a moderately increased BC risk. In the current study we investigated the status of three founder mutations in the CHEK2 gene (c.1100delC, R145W and I157T) using direct sequencing in 50 BC and 50 control samples. No mutations were detected. This result is in line with the postulated existence of a c.1100delC frequency gradient from the North to the South in Europe with higher frequencies in the Northern countries.

Keywords: breast cancer, CHEK2, mutations

Received November 25, 2013; Revised December 19, 2013; Accepted January 03, 2014

Citation: Amal ElAmrani, Khalid Moumad, Mohammed Attaleb, Mustapha Benhassou, Asta Försti, Moulay Mustapha Ennaji, Mohammed El Mzibri, Meriem Khyatti, Absence of CHEK2 1100delC, R145W and I157T Mutations in Breast Cancer in a Moroccan Population. Journal of Cancer Research and Treatment, 2 (1). 6-9. January 2014. doi:10.12691/jcrt-2-1-2

1. Introduction

Breast cancer (BC) is the most frequently diagnosed cancer and the leading cause of cancer death in females worldwide, accounting for 23% of total new cancer cases and 14% of total cancer deaths [1]. BC is a heterogeneous disease in which breast cells become abnormal and multiply to form a malignant tumor. In about 5 to 10% of cases, BC is due to hereditary genetic background caused by mutations in high penetrance susceptibility genes, which enhance familial risk [2]. About 16% of hereditary BCs can be attributed to germline mutations in the breast cancer 1 (BRCA1) and 2 (BRCA2) genes [3]. Mutations in other genes confer moderate risk of BC development. Among them, the Checkpoint kinase 2 (CHEK2) is a low penetrance gene mutated in less than 3% of BC cases [4].

CHEK2 is a functionally related DNA repair gene; it emerges as an important signal transducer that mediates cellular responses to DNA damage. In response to double-strand DNA breaks, CHEK2 activates p53 by phosphorylation [5]. CHEK2 is also a candidate tumor suppressor whose defects contribute to molecular pathogenesis of diverse types of human malignancies. Worldwide, different CHEK2 mutations have been reported to be associated with BC development. The c.1100delC is the first recurrent mutation in the CHEK2 gene to be reported as an important cause of BC [4]. Since then, numerous studies have documented the prevalence of this single founder mutation in various populations, but up to now few studies have been interested in its clinical impact. Thus far, five deleterious recurrent mutations in CHEK2 have been identified that confer about two-fold elevated risk of BC. These include in addition to the truncating mutation c.1100delC, the missense mutations R145W and I157T, the splice site mutation IVS2 + 1G > A and the large genomic 5,395 bp deletion (del5395) [6].

This preliminary study was planned to assess the frequencies of three CHEK2 mutations (c.1100delC, R145W and I157T) in a case-control study of 50 BC patients and 50 breast controls to evaluate the implication of these mutations in predisposition to BC in Morocco.

2. Materials and Methods

A total of 50 BC patients were recruited at the Obstetrics Service of the Ibn Rochd hospital (Casablanca, Morocco) between 2010 and 2012. Tumor tissue samples were obtained from biopsies collected for clinical diagnosis. The characteristics of the studied population and histopathological data are shown in Table 1. Fifty blood samples from healthy women, aged matched with BC patients, were collected to be used as a control group. The study protocol was approved by the Ethical Committee of Pasteur Institute of Morocco, and written informed consent was obtained from each study subject.

All the BC patients and controls were screened for the c.1100delC, R145W and I157T mutations. Mutations detection was done by PCR amplification and direct DNA sequencing as previously described [7]. PCR primers and the amplimers’ sizes are reported in Table 2.

Amplification reaction was performed in a total volume of 25 µl. The amplification mixture contained 50 pmol of each consensus primer, 200 µM of each dNTP, 0.5 units Taq DNA polymerase (Invitrogen / Life Technologies) and 2 µl of DNA sample in 1x Taq polymerase buffer. A touchdown PCR program was used for PCR amplification. PCR conditions were as follows: 94°C for 1 min; seven cycles of 94°C for 30 s, 60°C for 30 s, 68°C for 30 s; twenty eight cycles of 94°C for 30 s, 54°C for 30 s, 68°C for 30 s, followed by 70°C for 5 min and 12°C thereafter. Mutation positive and negative controls as well as a negative control for the PCR reaction were included in the analysis.

For DNA sequencing, the PCR products were purified by the Exo SaP-IT clean up system (USB, USA) and sequenced directly on an ABI 3130XL DNA analyzer (Applied Biosystems, Foster city, CA, USA), using Big Dye® Terminator v3.1 Cycle Sequencing Kit (Applied Biosystems, Foster city, CA, USA), according to manufacturer’s protocol. For each sample, PCR amplification and DNA sequencing were performed twice. The sequences obtained were then compared with the non-mutated reference sequence of CHEK2 gene available in the database Genatlas.

Table 1. Characteristics of the Breast cancer cases

Table 2. PCR primers

3. Results and Discussion

The CHEK2 c.1100delC heterozygosity may be associated with an increased risk of BC; however, it is unclear whether the evidence is sufficient to recommend genotyping in the clinical practice. Thus, the relevance of CHEK2 mutations as a screening target for an elevated risk of BC is of interest. Indeed, it is widely accepted that the risk of BC may be higher for women who have both a CHEK2 gene mutation and a family history of BC [8].

To our knowledge, no study has been conducted on CHEK2 mutations in Moroccan patients with BC. Therefore, we assessed the prevalence of these mutations in a case–control study of BC among Moroccan women. In the present study, the interest was focused on three CHEK2 variants that are known to affect protein function (c.1100delC, R145W, and I175T). The c.1100delC variant is a protein truncating mutation that abrogates CHEK2 kinase activity. R145W has been reported to have disrupted kinase activity and I175T is deficient in binding to BRCA1 and p53 [9].

In our study, neither cancer cases nor controls showed any of the mutations analyzed. Our data on the absence of the c.1100delC mutation in Morocco are in line with those of the previous studies ([10,11]) and support the notion that c.1100delC does not contribute to BC susceptibility in Mediterranean populations ([12,13]). In Spain, Osorio et al. did not detect the c.1100delC mutation in 856 samples analyzed [10]. The c.1100delC was also reported to be absent in Asian population. In North American populations, a very low frequency of CHEK2 c.1100delC mutation was reported [14] (Table 3). Interestingly, the highest frequency of CHEK2 1100delC has been found in patients from the North and the West of Europe, as compared to the southern countries exhibiting the lowest frequency (Italy and Spain) ([10,11]) (Table 3). These findings are in agreement with the hypothesis of the existence of a c.1100delC frequency gradient from the North-West to the South-East of Europe, caused by an ancestral common origin in the North [15]. This gradient may be more accentuated in the Mediterranean countries which may explain the absence of this mutation in the Moroccan population.

Table 3. Population’s frequencies of the studied Mutations in Chek2 gene

The CHEK2 I157T, a missense variant, alters the kinase activity of the CHEK2 protein. This variant has been reported in ethnically diverse populations and has been associated with a modest risk for developing BC among German and Belarusian populations [16] and for developing colon cancer among Polish and Finnish populations [17] (Table 3).

Other rare variants that adversely affect the CHEK2 protein function have been reported in ethnically diverse populations, and seem to marginally contribute to the overall burden of BC [18].

Our findings suggests that CHEK2 mutations is a rare event and play a negligible role in BC risk in Morocco and therefore the clinical relevance of CHEK2 mutations screening as a cancer predisposing gene is very limited.

Acknowledgement

This paper was supported by EU FP7/2007-2013 grant 260715.

References

[1]   | Jemal A, Bray F, Center MM, Ferlay J, Ward E, Forman D. Global cancer statistics. CA: a cancer journal for clinicians 2011; 61: 69-90.
[2]   | Claus EB, Schildkraut JM, Thompson WD, Risch NJ. The genetic attributable risk of breast and ovarian cancer. Cancer 1996; 77: 2318-24.
[3]   | Narod SA, Foulkes WD. BRCA1 and BRCA2: 1994 and beyond. Nature reviews Cancer 2004; 4: 665-76.
[4]   | Meijers-Heijboer H, van den Ouweland A, Klijn J, Wasielewski M, de Snoo A, Oldenburg R, et al. Low-penetrance susceptibility to breast cancer due to CHEK2 (*) 1100delC in noncarriers of BRCA1 or BRCA2 mutations. Nature genetics 2002; 31: 55-9.
[5]   | Chehab NH, Malikzay A, Appel M, Halazonetis TD. Chk2/hCds1 functions as a DNA damage checkpoint in G (1) by stabilizing p53. Genes & development 2000; 14: 278-88.
[6]   | Rashid MU, Muhammad N, Faisal S, Amin A, Hamann U. Constitutional CHEK2 mutations are infrequent in early-onset and familial breast/ovarian cancer patients from Pakistan. BMC cancer 2013; 13: 312.
[7]   | Kuusisto KM, Bebel A, Vihinen M, Schleutker J, Sallinen SL. Screening for BRCA1, BRCA2, CHEK2, PALB2, BRIP1, RAD50, and CDH1 mutations in high-risk Finnish BRCA1/2-founder mutation-negative breast and/or ovarian cancer individuals. Breast cancer research: BCR 2011; 13: R20.
[8]   | Cybulski C, Wokołorczyk D, Jakubowska A, Huzarski T, Byrski T, Gronwald J, et al. Risk of Breast Cancer in Women With a CHEK2 Mutation With and Without a Family History of Breast Cancer. Journal of Clinical Oncology 2011; 29: 3747-52.
[9]   | Wu X, Webster SR, Chen J. Characterization of tumor-associated Chk2 mutations. The Journal of biological chemistry 2001; 276: 2971-4.
[10]   | Osorio A, Rodriguez-Lopez R, Diez O, de la Hoya M, Ignacio Martinez J, Vega A, et al. The breast cancer low-penetrance allele 1100delC in the CHEK2 gene is not present in Spanish familial breast cancer population. International journal of cancer Journal international du cancer 2004; 108: 54-6.
[11]   | Caligo MA, Agata S, Aceto G, Crucianelli R, Manoukian S, Peissel B, et al. The CHEK2 c.1100delC mutation plays an irrelevant role in breast cancer predisposition in Italy. Human mutation 2004; 24: 100-1.
[12]   | Thirthagiri E, Cheong L, Yip C, Teo S-H. CHEK2* 1100delC does not contribute to risk to breast cancer among Malay, Chinese and Indians in Malaysia. Familial Cancer 2009; 8: 355-8.
[13]   | Weischer M, Bojesen SE, Nordestgaard BG. In Reply. Journal of Clinical Oncology 2008; 26: 2419-20.
[14]   | Iniesta MD, Gorin MA, Chien L-C, Thomas SM, Milliron KJ, Douglas JA, et al. Absence of CHEK2* 1100delC mutation in families with hereditary breast cancer in North America. Cancer genetics and cytogenetics 2010; 202: 136-40.
[15]   | González-Hormazábal P, Castro V, Blanco R, Gómez F, Peralta O, Waugh E, et al. Absence of CHEK2 1100delC mutation in familial breast cancer cases from a South American population. Breast Cancer Res Treat 2008; 110: 543-5.
[16]   | Bogdanova N, Enssen-Dubrowinskaja N, Feshchenko S, Lazjuk GI, Rogov YI, Dammann O, et al. Association of two mutations in the CHEK2 gene with breast cancer. International journal of cancer Journal international du cancer 2005; 116: 263-6.
[17]   | Kilpivaara O, Alhopuro P, Vahteristo P, Aaltonen LA, Nevanlinna H. CHEK2 I157T associates with familial and sporadic colorectal cancer. Journal of medical genetics 2006; 43: e34.
[18]   | Nevanlinna H, Bartek J. The CHEK2 gene and inherited breast cancer susceptibility. Oncogene 2006; 25: 5912-9.
[19]   | Consortium CBCC-C: CHEK2* 1100delC and susceptibility to breast cancer: a collaborative analysis involving 10,860 breast cancer cases and 9,065 controls from 10 studies. American journal of human genetics 2004; 74(6): 1175-1182.
[20]   | Friedrichsen DM, Malone KE, Doody DR, Daling JR, Ostrander EA: Frequency of CHEK2 mutations in a population based, case-control study of breast cancer in young women. Breast cancer research: BCR 2004; 6(6): R629-635.
[21]   | Offit K, Pierce H, Kirchhoff T, Kolachana P, Rapaport B, Gregersen P, Johnson S, Yossepowitch O, Huang H, Satagopan J et al: Frequency of CHEK2* 1100delC in New York breast cancer cases and controls. BMC medical genetics 2003; 4:1.
[22]   | Wagenius M, Borg A, Johansson L, Giwercman A, Bratt O: CHEK2* 1100delC is not an important high-risk gene in families with hereditary prostate cancer in southern Sweden. Scandinavian journal of urology and nephrology 2006; 40(1): 23-25.
[23]   | Einarsdottir K, Humphreys K, Bonnard C, Palmgren J, Iles MM, Sjolander A, Li Y, Chia KS, Liu ET, Hall P et al: Linkage disequilibrium mapping of CHEK2: common variation and breast cancer risk. PLoS medicine 2006; 3(6): e168.
[24]   | Shaag A, Walsh T, Renbaum P, Kirchhoff T, Nafa K, Shiovitz S, Mandell JB, Welcsh P, Lee MK, Ellis N et al: Functional and genomic approaches reveal an ancient CHEK2 allele associated with breast cancer in the Ashkenazi Jewish population. Human molecular genetics 2005; 14(4): 555-563.
[25]   | Kleibl Z, Novotny J, Bezdickova D, Malik R, Kleiblova P, Foretova L, Petruzelka L, Ilencikova D, Cinek P, Pohlreich P: The CHEK2 c.1100delC germline mutation rarely contributes to breast cancer development in the Czech Republic. Breast cancer research and treatment 2005; 90(2): 165-167.

[26]  
Bernstein JL, Teraoka SN, John EM, Andrulis IL, Knight JA, Lapinski R, Olson ER, Wolitzer AL, Seminara D, Whittemore AS et al: The CHEK2* 1100delC allelic variant and risk of breast cancer: screening results from the Breast Cancer Family Registry. Cancer epidemiology, biomarkers & prevention: a publication of the American Association for Cancer Research, cosponsored by the American Society of Preventive Oncology 2006; 15(2): 348-352.