Identification of PlexinD1 and AHDC1 as a putative interactors for Tip-1 protein

Manal Aly Shalaby,Lynne Hampson,Anthony Oliver,Ian Hampson 한국유전학회 2011 Genes & Genomics Vol.33 No.4

The class 1 PDZ domain Tip-1 protein was first identified as a binding partner for the Human T-Cell Leukaemia Virus type 1 (HTLV-1) Tax oncoprotein. It was later shown to interact with: the RhoA signaling effector Rhotekin, the Wnt signaling effector β-catenin and the E6 oncoprotein from high-risk HPV16 but not low-risk HPV6. These observations suggested that Tip-1 may be an important “hub” protein that is involved in pathways with a proven link to carcinogenesis. Based on these findings, it was decided to further characterize the cellular role of Tip-1 by carrying out a yeast two-hybrid screen to identify new binding partners in order to uncover potentially novel functions of this protein. This identified an intracellular fragment of the trans-membrane receptor plexin D1 and a C-terminal fragment of the AT hook DNA binding containing 1 (AHDC1) protein which had a carboxyl terminal PDZ binding domain consensus sequence. Both of these interactions were confirmed by yeast mating assay which was also used to show that mutant constructs of AHDC1 lacking the carboxyl PDZ binding site did not bind Tip-1. Immunofluorescent imaging of these proteins in HPV16 E6 expressing human C33A cervical carcinoma cells suggested they may co-localize.

Associations between Single Nucleotide Polymorphisms of COX-2 and MMP-2 Genes and Colorectal Cancer Susceptibility in the Saudi Population

Shalaby, Manal Ali,Nounou, Howaida Attia,Alanazi, Mohammad Saud,Alharby, Othman,Azzam, Nahla,Saeed, Hesham Mahmoud Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: It has been reported that COX-2 expression is associated with MMP-2 expression in thyroid and breast cancers, suggesting that MMPs are linked to COX-2-mediated carcinogenesis. Several polymorphisms within the MMP2 promoter region have been reported in cases with oncogenesis and tumor progression, especially in colorectal carcinogenesis. Materials and Methods: This research evaluated risk of association of the SNPs, including genes for COX-2 (AIG transition at +202) and MMP-2 (Crr transition at-1306), with colorectal cancer in 125 patients and 125 healthy controls. Results and Conclusions: Our data confirmed that MMP2 C-1306 T mutations were significantly more common in colon cancer patients than in our control Saudi population; p=O.0121. On the other hand in our study, there was no significant association between genotype distribution ofthe COX2 polymorphism and colorectal cancer; p=0.847. An elevated frequency ofthe mutated genotype in the control group as compared to the patients subjects indeed suggested that this polymorphism could decrease risk in the Saudi population. Our study confirmed that the polymorphisms that could affect the expressions of MMP-2 and COX-2 the colon cancer patients were significantly higher than that in the COX-2 negative group. The frequency of individuals with MMP2 polymorphisms in colon cancer patients was higher than individuals with combination of COX2 and MMP2 polymorphisms. Our study confirmed that individuals who carried the polymorphisms that could affect the expressions ofCOX2 are more susceptible to colon cancer. MMP2 regulatory polymorphisms could be considered as protective; further studies need to confirm the results with more samples and healthy subjects.

Novel Mutations of the PARP-1 Gene Associated with Colorectal Cancer in the Saudi Population

Alshammari, Atika Hazzaa,Shalaby, Manal Aly,Alanazi, Mohammad Saud,Saeed, Hesham Mahmoud Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Background: colorectal cancer (CRC) is the third most common type of cancers and the fourth leading cause of death worldwide. In Saudi Arabia, CRC accounts for 8.5% of all tumors; it ranks first among all cancers in males and third among females. The aim of this study was to link between different PARP-1 mutations and risk of CRC in Saudi population and to determine common variants of PARP-1 in Saudi CRC patients and normal individuals. Materials and Methods: DNA samples were isolated from fifty CRC patients and from a comparable number of control subjects then sequenced to detect different variations present in exons 3, 17, and 21 of the PARP-1 gene. Results and Conclusions: When comparing the genotype and allele frequencies of all detected SNPs in CRC patients with those in controls, we found none were significantly different for all variants even the most common SNP in PARP-1 gene (Val762Ala). However, two novel alterations in exon 21 were found to be associated with increased risk of CRC. The variants identified as (1) Lys933Asn [p-value 0.0318] and (2) Lys945Asn [p-value 0.0257]. Our results suggest that PARP-1 Lys933Asn and Lys945Asn alterations could be associated with increased risk of CRC in the Saudi population.

Association of XRCC1 Gene Polymorphisms with Breast Cancer Susceptibility in Saudi Patients

Al Mutairi, Fatima Masoud,Alanazi, Mohammed,Shalaby, Manal,Alabdulkarim, Huda A.,Pathan, Akbar Ali Khan,Parine, Narasimha Reddy Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Background: X-ray repair cross-complementing group 1 (XRCC1) plays a key role in the base excision repair pathway, as a scaffold protein that brings together proteins of the DNA repair complex. XRCC1 is reported to be a candidate influence on cancer risk. The aim of our present study was to assess the association of rs1799782 (Arg194Trp) and rs25487 (Arg399Gln) XRCC1 gene polymorphisms with breast cancer in the Saudi population. Materials and Methods: The two SNP's were analyzed in breast cancer patients and healthy control subjects. Genotypes were determined by TaqMan SNP genotype analysis technique and data were analyzed using Chi-square or t test and logistic regression analysis by SPSS16.0 software. Results and Conclusions: Results showed that rs1799782 significantly increased susceptibility to breast cancer with Arg/Trp, Arg/Trp+Trp/Trp genotypes and at Trp allele overall study. It also increased risk of breast cancer in older age patients (above 48) and with the ER positive category. XRCC1rs25487 (Arg399Gln) did not showed any significant association. In conclusion the XRCC1rs1799782 polymorphism may be involved in the etiology of breast cancer in the Saudi population. Confirmation of our findings in larger populations of different ethnicities is warranted.

Cytochrome P450 1A1, 2E1 and GSTM1 Gene Polymorphisms and Susceptibility to Colorectal Cancer in the Saudi Population

Saeed, Hesham Mahmoud,Alanazi, Mohammad Saud,Nounou, Howaida Attia,Shalaby, Manal Ali,Semlali, Abdelhabib,Azzam, Nahla,Aljebreen, Abdeulrahan,Alharby, Othman,Parine, Narasimha Reddy,Shaik, Jilani,Maha Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.6

Background: The Saudi population has experienced a sharp increase in colorectal and gastric cancer incidences within the last few years. The relationship between gene polymorphisms of xenobiotic metabolizing enzymes and colorectal cancer (CRC) incidence has not previously investigated among the Saudi population. The aim of the present study was to investigate contributions of CYP1A1, CYP2E1, and GSTM1 gene polymorphisms. Materials and Methods: Blood samples were collected from CRC patients and healthy controls and genotypes were determined by polymerase chain reaction restriction fragment length polymorphism and sequencing. Results and Conclusions: $CYP2E1^*6$ was not significantly associated with CRC development (odd ratio=1.29; confidence interval 0.68-2.45). A remarkable and statistically significant association was observed among patients with $CYP1Awt/^*2A$ (odd ratio=3.65; 95% confidence interval 1.39-9.57). The $GSTM1^*0/^*0$ genotype was found in 2% of CRC patients under investigation. The levels of CYP1A1, CYP2E1 and GSTM1 mRNA gene expression were found to be 4, 4.2 and 4.8 fold, respectively, by quantitative real time PCR. The results of the present case-control study show that the studied Saudi population resembles Caucasians with respect to the considered polymorphisms. Investigation of genetic risk factors and susceptibility gene polymorphisms in our Saudi population should be helpful for better understanding of CRC etiology.

Matrix Metalloproteinase-2 (-1306 C>T) Promoter Polymorphism and Risk of Colorectal Cancer in the Saudi Population

Saeed, Hesham Mahmoud,Alanazi, Mohammad Saud,Parine, Narasimha Reddy,Shaik, Jilani,Semlali, Abdelhabib,Alharbi, Othman,Azzam, Nahla,Aljebreen, Abdulrahman,Almadi, Majid,Shalaby, Manal Aly Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.10

Background: Matrix metalloproteinase-2 (MMP-2) is an enzyme with proteolytic activity against matrix proteins, particularly basement membrane constituents. A single nucleotide polymorphism (SNP) at -1306, which disrupts a Sp1-type promoter site (CCACC box), results in strikingly lower promoter activity with the T allele. In the present study, we investigated whether this MMP-2 genetic polymorphism might be associated with susceptibility to colorectal cancer (CRC) in the Saudi population. We also analyzed MMP-2 gene expression level sin CRC patients and 4 different cancer cell lines. Materials and Methods: TaqMan allele discrimination assays and DNA sequencing techniques were used to investigate the $C^{-1306}T$ SNP in the MMP-2 gene of Saudi colorectal cancer patients and controls. The MMP-2 gene expression level was also determined in 12 colon cancer tissue samples collected from unrelated patients and histologically normal tissues distant from tumor margins. Results and Conclusions: The MMP-2 $C^{-1306}T$ SNP in the promoter region was associated with CRC in our Saudi population and the MMP-2 gene expression level was found to be 10 times higher in CRC patients. The MMP-2 $C^{-1306}T$ SNP is significantly associated with CRC in the Saudi population and this finding suggested that MMP-2 variants might help predict CRC progression risk among Saudis. We propose that analysis of this gene polymorphism could assist in identification of patient subgroups at risk of a poor disease outcome.