Candidate Gene Analysis of Breast Cancer in the Jordanian Population of Arab Descent: A Case-Control Study

Matrix Metalloproteinase Gene Polymorphisms Are Associated with Breast Cancer in the Caucasian Women of Russia

We conducted this study to explore the association between matrix metalloproteinase (MMP) gene polymorphisms and breast cancer (BC) risk in the Caucasian women of Russia. In total, 358 affected (BC) and 746 unaffected (cancer-free) women were included in this case-control retrospective study. From BC-related genes in previous studies, ten single nucleotide polymorphisms (SNPs) in five MMP genes (MMP1, 2, 3, 8, 9) were genotyped. The BC risk was calculated by logistic regression (to evaluate the SNPs’ independent effects) and model-based multifactor dimensionality reduction (MB-MDR) (to identify SNP−SNP interactions) methods. The allelic variants’ distribution of c.836 A > G (rs17576) and c. 1721 C > G (rs2250889) MMP9 was significantly different between BC and cancer-free women: for G minor alleles, these SNPs manifested disorder protective effects (OR 0.82 and OR 0.67−0.71, respectively, pperm ≤ 0.035). Eleven haplotypes of six SNPs MMP9 were involved in BC risk (nine haplotypes) and protective (two haplotypes) effects. All 10 SNPs of the MMP genes examined were associated with BC within the 13 SNP−SNP interaction simulated models, with a pivotal role of the two-locus (rs17577 × rs3918242) MMP9 epistatic interaction (defined as 1.81% BC entropy within more than 60% of the genetic models). Under in silico bioinformatics, BC susceptibility MMP polymorphic loci are located in functionally active genome regions and impact genes expression and splicing “regulators” in the mammary gland. The biological pathways of BC MMP candidate genes are mainly realized due to metalloendopeptidase activity and extracellular matrix organization (structure, disassembly, metabolic process, etc.). In conclusion, our data show that MMP gene polymorphisms are related to BC susceptibility in the Caucasian women of Russia.

The Modifying Effect of Obesity on the Association of Matrix Metalloproteinase Gene Polymorphisms with Breast Cancer Risk

Objective: We investigated the possible modifying effect of obesity on the association of matrix metalloproteinase (MMP) gene polymorphisms with breast cancer (BC) risk. Methods: A total of 1104 women divided into two groups according to their body mass index (BMI): BMI ≥ 30 (119 BC, and 190 control) and BMI < 30 (239 BC, and 556 control) were genotyped for specially selected (according to their association with BC in the previous study) 10 single-nucleotide polymorphisms (SNP) of MMP1, 2, 3, 8, and 9 genes. Logistic regression association analysis was performed in each studied group of women (with/without obesity). Functional annotation of BC-correlated MMP polymorphic variants was analyzed by in silico bioinformatics. Results: We observed significant differences in the involvement of MMP SNPs in BC in obese and non-obese women. Polymorphic loci MMP9 (c.836 A > G (rs17576) and c. 1721 C > G (rs2250889)) were BC-protective factors in obese women (OR 0.71, allelic model, and OR 0.55, additive model, respectively). Genotypes TT MMP2 (c.-1306 C > T,rs243865) and AA MMP9 (c. 1331-163 G > A,rs3787268) determined BC susceptibility in non-obese women (OR 0.31, and OR 2.36, respectively). We found in silico substantial multidirectional influences on gene expression in adipose tissue BC-related polymorphic loci: BC risk allele A-rs3787268 in non-obese women is associated with low expression NEURL2, PLTP, RP3-337O18.9, SPATA25, and ZSWIM1, whereas BC risk allele A-rs17576 in obese women is associated with high expression in the same genes in visceral and/or subcutaneous adipose. Conclusions: our study indicated that obesity has a significant modifying effect on the association of MMP genes with BC risk in postmenopausal women.

Estimation of associations between MMP9 gene polymorphisms and breast cancer: Evidence from a meta-analysis

Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases, which play critical roles in cancer progression and metastasis. In recent years, many researchers have been studying the relationship between MMP9 and breast cancer. However, it still remains indecisive. Therefore, we conducted a meta-analysis to draw more accurate conclusions. A total of 21 relevant documents were retrieved, including 25 case-control studies. We quantitatively analyzed the data obtained. To clarify the relationship between MMP9 polymorphism and breast cancer susceptibility under different conditions, we also made a further subgroup analysis for each locus. In summary, we discovered that MMP9 rs3918242 rendered an increased risk for breast cancer, especially among Iranians and Indians. MMP9 rs3787268 could be a protective factor. MMP9 rs17576 and MMP9 rs2250889 have no association with breast cancer risk.

Association between matrix metalloproteinase 9 polymorphisms and breast cancer risk: An updated meta-analysis and trial sequential analysis

BACKGROUND

Numerous studies have sought associations between matrix metalloproteinase 9 (MMP-9) polymorphisms and breast cancer risk. However, these studies have yielded conflicting results. Hence, we performed an updated meta-analysis to clarify the effects of four MMP-9 gene polymorphisms (rs3918242, rs2250889, rs3787268, and rs17576) on breast cancer risk.

METHODS

A comprehensive literature search for eligible studies was conducted in five electronic databases, including PubMed, Embase and Web of Science, up to March 1, 2020. Summary odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations in random-effects models. For the reduction of type I errors, a trial sequential analysis (TSA) was performed.

RESULTS

Twenty-one studies (8813 breast cancer cases and 9323 controls) were included in the quantitative analysis. For rs3918242, the overall ORs were significant under allelic comparison (OR _{A vs. G} = 1.34; 95% CI 1.03, 1.74, P = 0.028) and the recessive genetic model (OR _{AA vs. GG+GA} = 1.40; 95% CI 1.06, 1.84, P = 0.016). For rs2250889, the ORs were significant under homozygote comparison (OR _{GG vs. CC} = 2.57; 95% CI 1.22, 5.42, P = 0.013), heterozygote comparison (OR _{GC vs. CC} = 2.48; 95% CI 1.17, 5.23, P = 0.018), and the dominant genetic model (OR _{GG+GC vs. CC} = 2.53; 95% CI 1.23, 5.20, P = 0.012). No associations were observed for rs3787268 or rs17576. The subgroup analyses indicated that the risk effect of the rs3918242 A allele was observed only among Asians. TSA showed that the findings for rs3918242, rs3787268, and rs17576 were robust, but many more patients are needed before definitive conclusions can be made for rs2250889.

CONCLUSION

Our meta-analysis suggests that MMP-9 rs3918242, but not rs3787268 and rs17576 polymorphisms, may be risk factors for breast cancer. The effect of rs2250889 needs further confirmation with a larger sample size.

The Associations of Common Genetic Susceptibility Variants with Breast Cancer in Jordanian Arabs: A Case-Control Study

OBJECTIVE

In Jordan, breast cancer (BC) affects a substantial proportion of Jordanian women, highlighting the need for studies to be carried out regarding the genetic component of the disease. The aim of the present study was to investigate the interaction between BC risk and prognosis and polymorphisms in genes (ATM, CASP8, FGFR2, FN1, IGF1, LSP1, MAP3K, MMP7, and RHOC) that were chosen for this study previously reported as having a role in the disease.

MATERIALS AND METHODS

Blood samples were collected from 242 BC patients and 231 disease-free volunteers recruited from the Jordanian population. DNA was extracted from blood and each sample was sent to the Australian Genome Research Facility for genotyping.

RESULTS

The rs1219648 SNP of the FGFR2 gene was the only investigated variant to show any direct association with BC in Jordanian women (p-value = 0.04). However, the CASP8rs6760993 SNP was found to be significantly associated with BC (p-value = 0.04) when using the dominant model. Other gene polymorphisms showed varying levels of association between some investigated SNPs and different BC risk and prognostic factors.

CONCLUSION

Despite reports to the contrary in other populations, most of the investigated genes and their respective SNPs did not show any significant association with BC in Jordanian women. Our results underline the need for independent BC research to be carried out in the Jordanian population to decipher the genetic basis of the disease.
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Familial/inherited cancer syndrome: a focus on the highly consanguineous Arab population

The study of hereditary cancer, which accounts for ~10% of cancer cases worldwide is an important subfield of oncology. Our understanding of hereditary cancers has greatly advanced with recent advances in sequencing technology, but as with any genetic trait, gene frequencies of cancer-associated mutations vary across populations, and most studies that have located hereditary cancer genes have been conducted on European or Asian populations. There is an urgent need to trace hereditary cancer genes across the Arab world. Hereditary disease is particularly prevalent among members of consanguineous populations, and consanguineous marriages are particularly common in the Arab world. There are also cultural and educational idiosyncrasies that differentiate Arab populations from other more thoroughly studied groups with respect to cancer awareness and treatment. Therefore, a review of the literature on hereditary cancers in this understudied population was undertaken. We report that BRCA mutations are not as prevalent among Arab breast cancer patients as they are among other ethnic groups, and therefore, other genes may play a more important role. A wide variety of germline inherited mutations that are associated with cancer are discussed, with particular attention to breast, ovarian, colorectal, prostate, and brain cancers. Finally, we describe the state of the profession of familial cancer genetic counselling in the Arab world, and the clinics and societies dedicated to its advances. We describe the complexities of genetic counselling that are specific to the Arab world. Understanding hereditary cancer is heavily dependent on understanding population-specific variations in cancer-associated gene frequencies.

The Association of IL-1 and HRAS Gene Polymorphisms with Breast Cancer Susceptibility in a Jordanian Population of Arab Descent: A Genotype-Phenotype Study

Breast cancer (BC) pathogenesis is poorly understood and not yet completely determined. BC susceptibility genes are responsible for 20% to 25% of breast cancer risk. The main objective of this study is to identify the genetic polymorphisms within the Harvey rat sarcoma viral oncogene homolog (HRAS1) and interleukin-1 receptor antagonist (IL1-Ra) genes in Jordanian BC female patients and to investigate the genetic association of these polymorphisms with BC. Samples were collected from 150 Jordanian BC patients and 187 healthy age-matched controls. PCR and PCR-RFLP techniques were used to identify genetic polymorphisms within these candidate genes. The single nucleotide polymorphism single nucleotide polymorphism (SNP) association web tool SNPStats (v. 3.6) was used to investigate the allelic and genotypic association with BC. Different statistical analyses were used to study the correlation between the investigated genetic variants and several prognosis factors of BC. A genetic association between BC susceptibility and Il-1β rs1143634 was found specifically at the allelic level of E1 as a risk allele (72% in the cases vs. 64.2% in the controls). Another genetic association was found in the IL-Ra gene (86-VNTR (variable number tandem repeat)), which presented one repeat allele (24.1% in cases vs. 15.59% in controls) and could be considered as a risk allele in Jordanian women. In contrast, this study found that there is no genetic association between Il-1β SNP rs16944 and BC. In addition, a significant association was found between the allelic level of the HRAS1 gene and BC susceptibility. Since this study is the first to be conducted on the genetic susceptibility of these genes to BC in the Jordanian population, more investigations on the link between BC and these variants are recommended to determine the impact of these polymorphisms on other ethnic groups.

Association between ESR1, ESR2, HER2, UGT1A4, and UGT2B7 polymorphisms and breast Cancer in Jordan: a case-control study

BACKGROUND

Breast cancer risk, development, and treatment are influenced by genetic variation in certain genes, namely those involved in cell proliferation, tumor suppression, and drug metabolism. In turn, the relevance of the aforementioned genetic variation to cancer depends on the ethnic group in question, highlighting the need for population-specific association studies. Therefore, the objective of the present study was to investigate the association between certain ESR1, ESR2, HER2, UGT1A4, and UGT2B7 single nucleotide polymorphisms and breast cancer.

METHODS

Blood samples were collected from 437 Jordanian-Arab breast cancer patients and healthy volunteers and subject to genotyping using the Sequenom MassARRAY® system (iPLEX GOLD).

RESULTS

Our findings show a significant association between breast cancer and the allelic (P = 0.02486879) and genotypic (P = 0.04793066) frequencies of the ESR1 polymorphism rs3798577, a result which was confirmed in different genetic models. No other investigated polymorphism showed a significant association with breast cancer itself in Jordanian Arabs, but the Rare Hz (GG) vs Het (AG) genetic model revealed an association of the disease with the ESR1 polymorphism rs3798577. However, several associations were found between certain polymorphisms and breast cancer's prognostic factors.

CONCLUSION

This study suggests that certain polymorphisms may increase the risk of breast cancer in the Jordanian-Arab population. Future research and clinical translation could incorporate the current results in preventative breast cancer approaches tailored for Jordanian-Arab patients.

Correlation between a variable number tandem repeat (VNTR) polymorphism in SMYD3 gene and breast cancer: A genotype-phenotype study

Genetic predisposition to breast cancer (BC) has become one of the most studied aspects of the disease. Advances in the field of cancer research have revealed the role of different genetic polymorphisms within genes of interest in the development of BC. This study aimed to explore the impact of a variable number tandem repeat (VNTR) genetic variant found within the SET and MYND domain containing protein 3 (SMYD3) gene on BC risk in Jordan and examine key clinical and pathological prognostic factors. Genotyping of blood samples from 180 cases with breast cancer and 180 healthy individuals from the Jordanian population was carried out via a combination of PCR and agarose gel electrophoresis. A highly significant association was found at level of genotype (P-value = 0.009) and allele (P-value = 0.0001) between BC development and the VNTR variant in the SMYD3 gene among Jordanian women. Moreover, we found that the VNTR of SMYD3 gene may interfere with BC risk among patients with different immunohistochemistry (IHC) profiles (P-value < 0.05). This study reported that there is a significant correlation between BC development and the VNTR in the SMYD3 gene. These findings can help alleviate the burden of BC in developing countries including Jordan and to fill the gaps in current literature. Since this study was carried out on Jordanian Arabs, more studies on the link between BC and the SMYD3 VNTR variant are recommended to determine this polymorphism's impact on other ethnic groups.

Association Of GSTM1, GSTT1 And GSTP1 Polymorphisms With Breast Cancer Among Jordanian Women

Purpose

Genetic predisposition to disease has become one of the most investigated risk factors in recent years, and breast cancer (BC) is no exception. In this study, we investigated specific genetic variants of three candidate genes belonging to the glutathione-S-transferase superfamily that have been implicated in increased risk of cancers.

Materials and methods

This case-control study comprised 241 Jordanian women who were diagnosed with BC in addition to 219 matched controls. Gel electrophoresis of PCR products was used to visualize and genotype both the GSTM1 and GSTT1 genes, while PCR-RFLP was employed to genotype the rs1695 of the GSTP1 gene.

Results

Our findings did not reveal any correlation between the investigated polymorphisms of GST genes and BC risk among Jordanian women. Otherwise, the combination of GSTM1 entire gene deletion and (GG) genotype of GSTP1 polymorphism (rs1695) was significantly associated with BC with p-value <0.05 (i.e. p-value was not significant after correcting for multiple comparison).

Conclusion

We suggest that the interaction between GSTM1 polymorphism and rs1695 of GSTP1 may influence BC development and progression among Jordanian women. More epidemiological studies are needed to provide a baseline for the underlying role of GSTs polymorphisms in tumorigenesis.

Association of CYP gene polymorphisms with breast cancer risk and prognostic factors in the Jordanian population

Background

Single nucleotide polymorphisms (SNPs) in several CYP genes have been associated with altered breast cancer (BC) risk in different populations. Despite this, there is a dearth of information on the roles of these SNPs in Jordanian BC patients. Therefore, this study aims to determine if there is any single nucleotide polymorphism (SNP) within CYP19A1, CYP2C19, CYP2C9, CYP1B1, CYP3A4, and CYP1A2 genes associated with BC in the Jordanian population. In addition, this work investigates the association between selected BC prognostic factors and variants of the aforementioned CYP candidate genes.

Methods

Blood samples were withdrawn from 221 BC patients and 218 healthy volunteers recruited from the Jordanian population. Genomic DNA was withdrawn and, after quantification and quality control, was genotyped using the Sequenom MassARRAY® system (iPLEX GOLD). Statistical analysis was then carried out to assess allelic and genotypic frequencies as well as genetic association between cases and controls.

Results

The CYP19A1 SNP rs7176005 (p < 0.0045) and the CYP1A2 SNP rs762551 (p = 0.004) were significantly associated with BC risk. However, no such association was found for the screened SNPs of the CYP2C9, CYP1B1, CYP2C19 and CYP3A4 genes. Regarding the prognostic factors of BC, several of the screened SNPs were associated with different pathological and clinical features.

Conclusions

Certain CYP genes, particularly CYP19A1 and CYP1A2, were associated with BC risk and development in the Jordanian population.

The influence of an IL-4 variable number tandem repeat (VNTR) polymorphism on breast cancer susceptibility

Backgrounds

Breast cancer (BC) is one of the most widespread cancers globally. Understanding the etiology of BC may help in determining the various risk factors involved in its malignancy. Certain genetic mutations are considered to play a key role in increasing the risk of BC.

Objectives

In this study, we explored the correlation between a variable number tandem repeat (VNTR) polymorphism in the IL-4 gene and BC.

Methods

PCR and subsequent gel electrophoresis were used to genotype this variant in 360 Jordanian women (180 BC patients and 180 controls). In addition, phenotype–genotype analysis was carried out.

Results

Our findings illustrate that there is no significant relationship between the variant genotypes in the IL-4 gene and BC among Jordanian females. Other than body mass index and tumor differentiation (p< 0.05), none of the clinical and pathological parameters of BC patients exhibited any association with the variant genotypes.

Conclusions

From this study, we propose that the IL-4 genetic variant does not impact BC development and progression but that it could influence the disease prognosis.

Correlation between Candidate Single Nucleotide Variants and Several Clinicopathological Risk Factors Related to Breast Cancer in Jordanian Women: A Genotype-Phenotype Study

This study aim to investigate the association of breast cancer risk and prognostic factors with single nucleotide variants of the BRCA1, BRCA2, DAPK1, MMP9, TOX3, and TP53 genes in Jordanian women. Blood samples were collected from 230 Jordanian breast cancer patients for use in DNA extraction followed by genotyping and subsequent statistical analysis. We found that two single nucleotide variants (SNVs) of the BRCA2 gene, namely rs1799944 and rs766173, were significantly associated with breastfeeding status. Likewise, the rs11141901 and rs1041326 SNVs of the DAPK1 gene were linked with co-morbidity (p-value = 0.002) and family history of BC (p-value = 0.015), while the rs1045042 SNV of the same gene was associated with both allergy (p-value = 0.001) and family history of BC (p-value = 0.02). Tumor differentiation was correlated with the DAPK1 SNVs rs11141901 (p-value = 0.041) and rs1041326 (p-value = 0.005). Additionally, the rs2250889 SNV of the MMP9 gene was significantly associated with HER2 status, whereas the TP53 SNVs rs12951053 and rs1042522 were associated with age at menarche (p-value = 0.043) and breastfeeding status (p-value = 0.013), respectively. In contrast, the TP53 SNV rs2287497 was significantly linked to age at first pregnancy (p-value = 0.001), smoking (p-value = 0.041), and axillary lymph node status (p-value = 6e^-4). No such association was found for the BRCA1 and TOX3 SNVs. The current findings suggest significant associations between certain SNVs and breast cancer risk and prognosis in Jordanian women.

Family specific genetic predisposition to breast cancer: results from Tunisian whole exome sequenced breast cancer cases

BACKGROUND

A family history of breast cancer has long been thought to indicate the presence of inherited genetic events that predispose to this disease. In North Africa, many specific epidemio-genetic characteristics have been observed in breast cancer families when compared to Western populations. Despite these specificities, the majority of breast cancer genetics studies performed in North Africa remain restricted to the investigation of the BRCA1 and BRCA2 genes. Thus, comprehensive data at a whole exome or whole genome level from local patients are lacking.

METHODS

A whole exome sequencing (WES) of seven breast cancer Tunisian families have been performed using a family-based approach. We focused our analysis on BC-TN-F001 family that included two affected members that have been sequenced using WES. Relevant variants identified in BC-TN-F001 have been confirmed using Sanger sequencing. Then, we conducted an integrative analysis by combining our results with those from other WES studies in order to figure out the genetic transmission model of the newly identified genes. Biological network construction and protein-protein interactions analyses have been performed to decipher the molecular mechanisms likely accounting for the role of these genes in breast cancer risk.

RESULTS

Sequencing, filtering strategies, and validation analysis have been achieved. For BC-TN-F001, no deleterious mutations have been identified on known breast cancer genes. However, 373 heterozygous, exonic and rare variants have been identified on other candidate genes. After applying several filters, 12 relevant high-risk variants have been selected. Our results showed that these variants seem to be inherited in a family specific model. This hypothesis has been confirmed following a thorough analysis of the reported WES studies. Enriched biological process and protein-protein interaction networks resulted in the identification of four novel breast cancer candidate genes namely MMS19, DNAH3, POLK and KATB6.

CONCLUSIONS

In this first WES application on Tunisian breast cancer patients, we highlighted the impact of next generation sequencing technologies in the identification of novel breast cancer candidate genes which may bring new insights into the biological mechanisms of breast carcinogenesis. Our findings showed that the breast cancer predisposition in non-BRCA families may be ethnic and/or family specific.