Reham Helwa - Academia.edu (original) (raw)
Papers by Reham Helwa
Biochemical Genetics
Covid-19 crisis did hit many socio-economic aspects in the whole world. In the scientific researc... more Covid-19 crisis did hit many socio-economic aspects in the whole world. In the scientific research, the problem is getting even worse, since most of materials and consumable are allocated to the health sector. Many research laboratories around the world have big delay in receiving their purchases to accomplish their research projects. In the developing countries, the situation is much more difficult, since most of the funding resources are directed to the Covid-19 crisis and there is a notable increase in reagents’ prices. Therefore, the aim of the present study is to make a homemade reagents for RNA purification from eukaryotic cells/tissues. The homemade phenol-based RNA extraction reagents were prepared using saturated phenol pH 4.3 (adjusted by 0.5 M citrate buffer) and guanidine thiocyanate. To validate the phenol-based reagent, RNA was purified from different biological samples (cell line, tissues, and fungi) using homemade phenol-based versus a commercial one. Concentration o...
Oncology Research
Galectins are sticky molecules that bind to β-galactoside. Their interactions render them essenti... more Galectins are sticky molecules that bind to β-galactoside. Their interactions render them essential players in many cellular processes. The imbalance of galectin expression was reported in many diseases. In cancer, galectins interact with the extracellular matrix, evade the immune system, and potentially have broad interactions with blood components. In the last ten years, since 2010, we did focus on galectin research in different cancer types. Our findings showed an interaction between cancer cells and erythrocytes via galectin-4. Moreover, we found that upregulation of galectins was associated with lymph node metastasis in ovarian cancers. Hence, with this, we shortly review some important aspects of galectins and their potential importance in more profound understanding of cancer progression and the field of cancer biomarkers. Galectins are Potentially Supporting Cancer Cells to Invade and Metastasize via Interaction with Blood Components In 2017, an interaction between cancer cells and erythrocytes was reported and interpreted by galectin-4 interaction with the blood group antigen (Fig. 1). Displacement of galectin-4 to attachment points of cancer cells and erythrocytes was noticed. Also, we found in this article, a co-localization of galectin-4 and blood group antigen was seen using double fluorescent immunostaining. Moreover, a morphological deformation of red blood cells was seen to be associated with this interaction [1]. In this model, interacting cells were dividing without the presence of an attachment surface. In addition, developing lamellipodia/filopodia was noticed after interactions [1]. According to the structure of galectins, all surface/secreted galectins might interact with erythrocytes. Thus, many questions have been raised regarding the dysregulation of galectins in cancer. For instance, is the upregulation of galectins related to invasive cancers or lymph node metastasis? Thus, our group sought mRNA expression in many types of cancers, including AML [2,3], ovarian [4], endometrial, and breast (unpublished). Consistent with our hypothesis, in ovarian cancer, we found that galectin-9 might be a potential marker for lymph node metastasis [4]. Supportive Biological Evidence and Functions Related to Galectins and Cancer Galectin family Galectins are protein family that have a high affinity for binding to β-galactoside like N-acetyllactosamine via Nlinked or O-linked glycosylation. Galectins are a structurally associated family containing at least one carbohydrate recognition domain (CRD) [5,6]. The CRD of this family is folded into a β-sandwich structure consisting of two stretched antiparallel β-sheets. Galectin's ligand binds to the groove formed by β-sandwich [7]. Up to now, there are sixteen members of the galectins family. Depending on their structure, galectins are categorized into three different types: prototype, tandem repeat or chimera. Prototypical galectins (LGALS1, 2, 5, 7, 10, 11, 13, 14 and 15) contain one CRD that can dimerize. Tandem galectins (LGALS4, 6, 8, 9, and 12) are at least two CRD linked together by a small peptide domain. Galecin-3 is the only member that contains one CRD linked to the N-terminal non-lectin domain [8,9]. These structural aspects render them a key players in several cellular processes, as shown in Fig. 2. Subcellular localization Galectins display a wide range of distribution (Table 1
AMB Express
As a consequence of Covid-19 pandemic, the basic lab consumables are in shortage, especially in t... more As a consequence of Covid-19 pandemic, the basic lab consumables are in shortage, especially in the low-income countries. Thus, the main objective of the present study is to develop and evaluate homemade solution to isolate plasmid. To pursue this objective, RNase A was overexpressed in Bl21 DE3 cells (E. coli strain) and prepared as crude refolding reaction with proper activity. Also, lysis buffers, neutralization buffer, and washing buffers were prepared. The homemade miniprep kit showed successful isolation of the px48SpCas9 plasmid. The prepared plasmid purity was enough to be used successfully in PCR amplification. In addition, to get extra benefits from this study, seven primers were designed to match the plasmid backbone to produce DNA ladder (100–1500 bp). In conclusion, we were able to have attainable working solutions for plasmid miniprep and DNA ladder.
World Journal of Surgical Oncology, Sep 1, 2022
Cancer Research
This abstract was withdrawn by the authors.
AMB Express
A worldwide shortage of molecular biology consumables is in surge. This includes filter tips, nuc... more A worldwide shortage of molecular biology consumables is in surge. This includes filter tips, nucleic acid purification kits, polymerases, reverse-transcriptase, and different types of reagents which are included in viral diagnostic kits. In developing countries, the problem is even worse, since there is few capital enterprise to adopt this kind of industry. So, our aim is to develop a suitable, functional, comparable to commercial ones, and affordable in-house protocol to purify viral RNA. We sought some published and commercial RNA purification solutions to set-up an in-house protocol for viral RNA extraction. Solution was prepared accordingly. Also, LPA (linearized polyacrylamide) carrier was evaluated. The whole setting of in-house solutions with addition of LPA carrier was compared to QIAamp viral RNA minikit solutions. Our results showed that linearized polyacrylamide (LPA) carrier in homemade solutions is comparable to poly A carrier which is used in the most commercial kit. ...
THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY (Zoology)
Twenty years ago, working with molecular biology research was very costly worldwide. Later on, af... more Twenty years ago, working with molecular biology research was very costly worldwide. Later on, after distributing the know-how of many reagents, it becomes more feasible to work in this field with reasonable costs. In addition, the optimization of large-scale production of enzymes, kits, lab consumables, and reagents made a big revolution in research and diagnostics. So, having affordable technologies in any molecular biology laboratory is an aim itself, especially in developing countries. After Covid-19 crisis, the need of molecular biology reagents is in surge. However, consumables’ prices, delayed orders, and shortage are the prominent issues after the pandemic. Thus, in the present study, homemade solutions were investigated for RNA purification from HepG2 and huh7 cells. The RNA was successfully purified by the homemade solutions and amplified using qRT-PCR. However DNA contamination was encountered which could be eliminated simply by DNase I digestion or designing proper prime...
Revista de Senología y Patología Mamaria, 2022
While large GWAS analyses have not found convincing associations between <i>MDM2</i> ... more While large GWAS analyses have not found convincing associations between <i>MDM2</i> promoter SNP55 and gynaecological cancers, SNP55 is in linkage disequilibrium with two other functional SNPs in the same promoter, likely to obscure associations between single SNPs and cancer risk. Here, we assessed the impact of SNP55 on risk of endometrial and ovarian cancer, including sub-analyses stratified for other functional SNPs in the region. Using a custom LightSNiP assay, we genotyped SNP55 in two large hospital-based cohorts of patients with ovarian (n = 1,332) and endometrial (n = 1,363) cancer and compared genotypes to healthy female controls (n = 1,858). Among individuals harbouring the SNP309TT genotype, the minor SNP55T-allele was associated with a reduced risk of endometrial (dominant model: OR = 0.63; CI = 0.45–0.88; <i>p</i> = 0.01). Regardless of the genotype in neighbouring SNPs, the SNP55T-allele was also associated with a reduced risk of endometrial c...
Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 whi... more Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 which encode kinase and helical domains of the protein and may result in its activation. PIK3CA activating mutations were previously shown to predict lower pathologic complete response (pCR) in HER2-positive breast cancer cases undergoing neoadjuvant human epidermal growth factor receptor 2-targeting therapy. Hence, the present work was conducted to estimate the mutation frequency in PIK3CA in 51 HER2-positive patients by direct sequencing. Our results showed 8 out of 51 (15.7%) to harbor PIK3CA mutations in either exon 9 or 20, or both. Three patients had mutations in both exons 9 and 20. Seven (13.7%) possess missense mutations in exon 20 which changed the amino acid sequence of the protein (H1047R, M1040I, and G1049G). Only four cases harbored mutations in exon 9, changing the codon sequences (E545K E545A, and R524K). Taking the clinicopathological data to account, the mutation frequency...
cancer screening When screening is recommended, it generally starts with fecal occult blood testi... more cancer screening When screening is recommended, it generally starts with fecal occult blood testing (FOBT). Many colorectal cancers bleed into intestinal lumen, and fecal occult blood tests can detect the presence of blood that is otherwise unapparent through simple inspection. As blood passes through the gastrointestinal tract, it becomes degraded, and depending upon the site at which the hemorrhage occurs, blood products in the stool will vary. For example, if a lesion is located in the proximal colon, hemoglobin will be completely digested and will be metabolized by bacteria into porphyrins. However, if the lesion is in the distal colon, hemoglobin and heme will remain mostly intact and unchanged. The design of the FOBT, therefore, must take these acids stretches fused to the CRD [9,10]. Galectins are involved in several cellular functions. They play different roles in cell-cell and cell-matrix adhesion [47]. Some galectins are secreted from the cell through non-classical pathway, since galectins a signal sequence that is required for the classical secretion pathway [48,49]. Also, galectins could be found as intracellular proteins in different subcellular locations [50]. Moreover, galectins play a rule in regulating cell survival and signaling, chemotaxis, and cytokines secretion and consequently acting as a regulator of immune cell homeostasis and inflammation [51,52].
Figure S1. Gene expression correlation analysis extended. Figure S2. DNA sequence verification of... more Figure S1. Gene expression correlation analysis extended. Figure S2. DNA sequence verification of SDHC and SDHD CRIPSR/Cas9 modifications. Figure S3. Characterization of EMT in MCF10A cells overexpressing TWIST or SNAI2. Figure S4. Western blot analysis of HIF-1Îą in MCF7 and MCF10A cells. Table S1. Gene expression correlation analysis, in cell lines. Table S2. Gene expression correlation analysis towards specific gene panels. Table S3. Lists of probes, antibodies, and dyes. (PDF 7335 kb)
Supplemental methods (PDF 26 kb)
Asian Pacific Journal of Cancer Prevention : APJCP, 2017
Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 whi... more Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 which encode kinase and helical domains of the protein and may result in its activation. PIK3CA activating mutations were previously shown to predict lower pathologic complete response (pCR) in HER2-positive breast cancer cases undergoing neoadjuvant human epidermal growth factor receptor 2-targeting therapy. Hence, the present work was conducted to estimate the mutation frequency in PIK3CA in 51 HER2-positive patients by direct sequencing. Our results showed 8 out of 51 (15.7%) to harbor PIK3CA mutations in either exon 9 or 20, or both. Three patients had mutations in both exons 9 and 20. Seven (13.7%) possess missense mutations in exon 20 which changed the amino acid sequence of the protein (H1047R, M1040I, and G1049G). Only four cases harbored mutations in exon 9, changing the codon sequences (E545K E545A, and R524K). Taking the clinicopathological data to account, the mutation frequency...
Biomarkers, 2021
Background: While large GWAS analyses have not found convincing associations between MDM2 promote... more Background: While large GWAS analyses have not found convincing associations between MDM2 promoter SNP55 and gynaecological cancers, SNP55 is in linkage disequilibrium with two other functional SNPs in the same promoter, likely to obscure associations between single SNPs and cancer risk. Here, we assessed the impact of SNP55 on risk of endometrial and ovarian cancer, including sub-analyses stratified for other functional SNPs in the region. Material and methods: Using a custom LightSNiP assay, we genotyped SNP55 in two large hospitalbased cohorts of patients with ovarian (n ¼ 1,332) and endometrial (n ¼ 1,363) cancer and compared genotypes to healthy female controls (n ¼ 1,858). Results: Among individuals harbouring the SNP309TT genotype, the minor SNP55T-allele was associated with a reduced risk of endometrial (dominant model: OR ¼ 0.63; CI ¼ 0.45-0.88; p ¼ 0.01). Regardless of the genotype in neighbouring SNPs, the SNP55T-allele was also associated with a reduced risk of endometrial cancer before 50 years of age (dominant model: OR ¼ 0.56; CI ¼ 0.34-0.90; p ¼ 0.02). No association between SNP55 status and ovarian cancer risk was observed. Conclusions: MDM2 SNP55T-allele may correlate with reduced risk for endometrial cancer in a SNP309T-, but not SNP309G, context.
Cancer & Metabolism, 2019
Background: Epithelial to mesenchymal transition (EMT) is a well-characterized process of cell pl... more Background: Epithelial to mesenchymal transition (EMT) is a well-characterized process of cell plasticity that may involve metabolic rewiring. In cancer, EMT is associated with malignant progression, tumor heterogeneity, and therapy resistance. In this study, we investigated the role of succinate dehydrogenase (SDH) as a potential key regulator of EMT. Methods: Associations between SDH subunits and EMT were explored in gene expression data from breast cancer patient cohorts, followed by in-depth studies of SDH suppression as a potential mediator of EMT in cultured cells. Results: We found an overall inverse association between EMT and the SDH subunit C (SDHC) when analyzing gene expression in breast tumors. This was particularly evident in carcinomas of basal-like molecular subtype compared to non-basal-like tumors, and a low SDHC expression level tended to have a prognostic impact in those patients. Studies in cultured cells revealed that EMT was induced by SDH inhibition through SDHC CRISPR/Cas9 knockdown or by the enzymatic inhibitor malonate. Conversely, overexpression of EMT-promoting transcription factors TWIST and SNAI2 caused decreased levels of SDHB and C and reduced rates of SDH-linked mitochondrial respiration. Cells overexpressing TWIST had reduced mitochondrial mass, and the organelles were thinner and more fragmented compared to controls. Conclusions: Our findings suggest that downregulation of SDHC promotes EMT and that this is accompanied by structural remodeling of the mitochondrial organelles. This may confer survival benefits upon exposure to hostile microenvironment including oxidative stress and hypoxia during cancer progression.
Indian Journal of Hematology and Blood Transfusion, 2017
Although the clinical features of isocitrate dehydrogenase (IDH) genetic aberrations have been we... more Although the clinical features of isocitrate dehydrogenase (IDH) genetic aberrations have been wellcharacterized in acute myeloid leukemia (AML), definitive information on their prognostic significance is lacking. We aimed to explore the prognostic significance of IDH gene alterations in an Egyptian cohort of adult patients with de novo AML. Diagnostic peripheral blood samples from 51 AML patients were analyzed for the presence of mutations/ SNPs in exon 4 of IDH1 and IDH2 genes using polymerase chain reaction amplification followed by direct sequencing. IDH mutational status had no impact on event-free survival (EFS) and overall survival (OS), whereas the presence of IDH1 315C[T SNP was significantly associated with inferior EFS (P = 0.037) and OS (P = 0.034) as compared with wild-type IDH1. IDH1 315C[T SNP but not IDH mutations is associated with unfavorable outcomes, suggesting that AML patients with IDH1 315C[T SNP can represent a new subgroup of patients which allows refined risk stratification.
Cellular Oncology, 2017
Background The ability of tumor cells to invade and metastasize is relevant to the process of can... more Background The ability of tumor cells to invade and metastasize is relevant to the process of cancer progression and, as such, it represents an obstacle to cancer cure. So far, limited information is available on interactions between circulating tumor cells and blood cells. It is well-documented that galectin-4 is upregulated in many types of tumor cells and is involved in metastasis. Here, we address the hypothesis that tumor cells may interact with red blood cells (RBCs) via galectin-4. Methods High galectin-4 expressing colon, normal pancreatic and pancreatic cancer-derived cell lines (n = 5) were incubated with peripheral blood cells from different donors. Their interactions and associated proteins were examined by immunostaining and live cell imaging. Results We found that (endogenous or exogenous) galectin-4 expressing tumor cells interact directly with RBCs. We also observed an accumulation of galectin-4 and human blood group antigens at the contact sites between these cells. By comparing the number of RBCs attaching to each tumor cell, we found that cells with high pre-incubation expression levels of galectin-4 attached significantly more RBCs than those with low expression levels (p < 1 × 10 −7). Conversely, we found that RBC attachment induces galectin-4 expression in tumor cells. Conclusions From our data we conclude that tumor cells directly interact with red blood cells via galectin-4.
Asian Pacific Journal of Cancer Prevention, 2015
The present study was conducted to investigate the effect of γ-radiation alone or combined with a... more The present study was conducted to investigate the effect of γ-radiation alone or combined with a cytotoxic drug, simvastatin, on viability and cell cycling of a myeloma cell line. P3NS1 myeloma cells were treated with the selected dose of simvastatin (0.1μM/l) 24 hours prior to γ-irradiation (0.25, 0.5 and 1Gy). The cell viability, induction of apoptosis, cell death, cell cycling, generation of ROS, and expression of P53, Bax, Bcl2, caspase3, PARP1 and Fas genes were estimated. The results indicated that simvastatin (0.1μM/l) treatment for 24 hours prior to γ-irradiation increased cell death to 37.5% as compared to 4.81% by radiation (0.5Gy) alone. It was found that simvastatin treatment before irradiation caused arrest of cells in G0/G1 and G2/M phases as assessed using flow cytometry. Interestingly, simvastatin treatment of P3NS1 cells increased the intracellular ROS production and decreased antioxidant enzyme activity with increased P53, Bax and Caspase3 gene expression while that of Bcl2 was decreased. Consequently, our results indicated that pre-treatment with simvastatin increased radio sensitivity of myeloma tumor cells in addition to apoptotic effects through an intrinsic mitochondrial pathway.
Biochemical Genetics
Covid-19 crisis did hit many socio-economic aspects in the whole world. In the scientific researc... more Covid-19 crisis did hit many socio-economic aspects in the whole world. In the scientific research, the problem is getting even worse, since most of materials and consumable are allocated to the health sector. Many research laboratories around the world have big delay in receiving their purchases to accomplish their research projects. In the developing countries, the situation is much more difficult, since most of the funding resources are directed to the Covid-19 crisis and there is a notable increase in reagents’ prices. Therefore, the aim of the present study is to make a homemade reagents for RNA purification from eukaryotic cells/tissues. The homemade phenol-based RNA extraction reagents were prepared using saturated phenol pH 4.3 (adjusted by 0.5 M citrate buffer) and guanidine thiocyanate. To validate the phenol-based reagent, RNA was purified from different biological samples (cell line, tissues, and fungi) using homemade phenol-based versus a commercial one. Concentration o...
Oncology Research
Galectins are sticky molecules that bind to β-galactoside. Their interactions render them essenti... more Galectins are sticky molecules that bind to β-galactoside. Their interactions render them essential players in many cellular processes. The imbalance of galectin expression was reported in many diseases. In cancer, galectins interact with the extracellular matrix, evade the immune system, and potentially have broad interactions with blood components. In the last ten years, since 2010, we did focus on galectin research in different cancer types. Our findings showed an interaction between cancer cells and erythrocytes via galectin-4. Moreover, we found that upregulation of galectins was associated with lymph node metastasis in ovarian cancers. Hence, with this, we shortly review some important aspects of galectins and their potential importance in more profound understanding of cancer progression and the field of cancer biomarkers. Galectins are Potentially Supporting Cancer Cells to Invade and Metastasize via Interaction with Blood Components In 2017, an interaction between cancer cells and erythrocytes was reported and interpreted by galectin-4 interaction with the blood group antigen (Fig. 1). Displacement of galectin-4 to attachment points of cancer cells and erythrocytes was noticed. Also, we found in this article, a co-localization of galectin-4 and blood group antigen was seen using double fluorescent immunostaining. Moreover, a morphological deformation of red blood cells was seen to be associated with this interaction [1]. In this model, interacting cells were dividing without the presence of an attachment surface. In addition, developing lamellipodia/filopodia was noticed after interactions [1]. According to the structure of galectins, all surface/secreted galectins might interact with erythrocytes. Thus, many questions have been raised regarding the dysregulation of galectins in cancer. For instance, is the upregulation of galectins related to invasive cancers or lymph node metastasis? Thus, our group sought mRNA expression in many types of cancers, including AML [2,3], ovarian [4], endometrial, and breast (unpublished). Consistent with our hypothesis, in ovarian cancer, we found that galectin-9 might be a potential marker for lymph node metastasis [4]. Supportive Biological Evidence and Functions Related to Galectins and Cancer Galectin family Galectins are protein family that have a high affinity for binding to β-galactoside like N-acetyllactosamine via Nlinked or O-linked glycosylation. Galectins are a structurally associated family containing at least one carbohydrate recognition domain (CRD) [5,6]. The CRD of this family is folded into a β-sandwich structure consisting of two stretched antiparallel β-sheets. Galectin's ligand binds to the groove formed by β-sandwich [7]. Up to now, there are sixteen members of the galectins family. Depending on their structure, galectins are categorized into three different types: prototype, tandem repeat or chimera. Prototypical galectins (LGALS1, 2, 5, 7, 10, 11, 13, 14 and 15) contain one CRD that can dimerize. Tandem galectins (LGALS4, 6, 8, 9, and 12) are at least two CRD linked together by a small peptide domain. Galecin-3 is the only member that contains one CRD linked to the N-terminal non-lectin domain [8,9]. These structural aspects render them a key players in several cellular processes, as shown in Fig. 2. Subcellular localization Galectins display a wide range of distribution (Table 1
AMB Express
As a consequence of Covid-19 pandemic, the basic lab consumables are in shortage, especially in t... more As a consequence of Covid-19 pandemic, the basic lab consumables are in shortage, especially in the low-income countries. Thus, the main objective of the present study is to develop and evaluate homemade solution to isolate plasmid. To pursue this objective, RNase A was overexpressed in Bl21 DE3 cells (E. coli strain) and prepared as crude refolding reaction with proper activity. Also, lysis buffers, neutralization buffer, and washing buffers were prepared. The homemade miniprep kit showed successful isolation of the px48SpCas9 plasmid. The prepared plasmid purity was enough to be used successfully in PCR amplification. In addition, to get extra benefits from this study, seven primers were designed to match the plasmid backbone to produce DNA ladder (100–1500 bp). In conclusion, we were able to have attainable working solutions for plasmid miniprep and DNA ladder.
World Journal of Surgical Oncology, Sep 1, 2022
Cancer Research
This abstract was withdrawn by the authors.
AMB Express
A worldwide shortage of molecular biology consumables is in surge. This includes filter tips, nuc... more A worldwide shortage of molecular biology consumables is in surge. This includes filter tips, nucleic acid purification kits, polymerases, reverse-transcriptase, and different types of reagents which are included in viral diagnostic kits. In developing countries, the problem is even worse, since there is few capital enterprise to adopt this kind of industry. So, our aim is to develop a suitable, functional, comparable to commercial ones, and affordable in-house protocol to purify viral RNA. We sought some published and commercial RNA purification solutions to set-up an in-house protocol for viral RNA extraction. Solution was prepared accordingly. Also, LPA (linearized polyacrylamide) carrier was evaluated. The whole setting of in-house solutions with addition of LPA carrier was compared to QIAamp viral RNA minikit solutions. Our results showed that linearized polyacrylamide (LPA) carrier in homemade solutions is comparable to poly A carrier which is used in the most commercial kit. ...
THE EGYPTIAN JOURNAL OF EXPERIMENTAL BIOLOGY (Zoology)
Twenty years ago, working with molecular biology research was very costly worldwide. Later on, af... more Twenty years ago, working with molecular biology research was very costly worldwide. Later on, after distributing the know-how of many reagents, it becomes more feasible to work in this field with reasonable costs. In addition, the optimization of large-scale production of enzymes, kits, lab consumables, and reagents made a big revolution in research and diagnostics. So, having affordable technologies in any molecular biology laboratory is an aim itself, especially in developing countries. After Covid-19 crisis, the need of molecular biology reagents is in surge. However, consumables’ prices, delayed orders, and shortage are the prominent issues after the pandemic. Thus, in the present study, homemade solutions were investigated for RNA purification from HepG2 and huh7 cells. The RNA was successfully purified by the homemade solutions and amplified using qRT-PCR. However DNA contamination was encountered which could be eliminated simply by DNase I digestion or designing proper prime...
Revista de Senología y Patología Mamaria, 2022
While large GWAS analyses have not found convincing associations between <i>MDM2</i> ... more While large GWAS analyses have not found convincing associations between <i>MDM2</i> promoter SNP55 and gynaecological cancers, SNP55 is in linkage disequilibrium with two other functional SNPs in the same promoter, likely to obscure associations between single SNPs and cancer risk. Here, we assessed the impact of SNP55 on risk of endometrial and ovarian cancer, including sub-analyses stratified for other functional SNPs in the region. Using a custom LightSNiP assay, we genotyped SNP55 in two large hospital-based cohorts of patients with ovarian (n = 1,332) and endometrial (n = 1,363) cancer and compared genotypes to healthy female controls (n = 1,858). Among individuals harbouring the SNP309TT genotype, the minor SNP55T-allele was associated with a reduced risk of endometrial (dominant model: OR = 0.63; CI = 0.45–0.88; <i>p</i> = 0.01). Regardless of the genotype in neighbouring SNPs, the SNP55T-allele was also associated with a reduced risk of endometrial c...
Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 whi... more Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 which encode kinase and helical domains of the protein and may result in its activation. PIK3CA activating mutations were previously shown to predict lower pathologic complete response (pCR) in HER2-positive breast cancer cases undergoing neoadjuvant human epidermal growth factor receptor 2-targeting therapy. Hence, the present work was conducted to estimate the mutation frequency in PIK3CA in 51 HER2-positive patients by direct sequencing. Our results showed 8 out of 51 (15.7%) to harbor PIK3CA mutations in either exon 9 or 20, or both. Three patients had mutations in both exons 9 and 20. Seven (13.7%) possess missense mutations in exon 20 which changed the amino acid sequence of the protein (H1047R, M1040I, and G1049G). Only four cases harbored mutations in exon 9, changing the codon sequences (E545K E545A, and R524K). Taking the clinicopathological data to account, the mutation frequency...
cancer screening When screening is recommended, it generally starts with fecal occult blood testi... more cancer screening When screening is recommended, it generally starts with fecal occult blood testing (FOBT). Many colorectal cancers bleed into intestinal lumen, and fecal occult blood tests can detect the presence of blood that is otherwise unapparent through simple inspection. As blood passes through the gastrointestinal tract, it becomes degraded, and depending upon the site at which the hemorrhage occurs, blood products in the stool will vary. For example, if a lesion is located in the proximal colon, hemoglobin will be completely digested and will be metabolized by bacteria into porphyrins. However, if the lesion is in the distal colon, hemoglobin and heme will remain mostly intact and unchanged. The design of the FOBT, therefore, must take these acids stretches fused to the CRD [9,10]. Galectins are involved in several cellular functions. They play different roles in cell-cell and cell-matrix adhesion [47]. Some galectins are secreted from the cell through non-classical pathway, since galectins a signal sequence that is required for the classical secretion pathway [48,49]. Also, galectins could be found as intracellular proteins in different subcellular locations [50]. Moreover, galectins play a rule in regulating cell survival and signaling, chemotaxis, and cytokines secretion and consequently acting as a regulator of immune cell homeostasis and inflammation [51,52].
Figure S1. Gene expression correlation analysis extended. Figure S2. DNA sequence verification of... more Figure S1. Gene expression correlation analysis extended. Figure S2. DNA sequence verification of SDHC and SDHD CRIPSR/Cas9 modifications. Figure S3. Characterization of EMT in MCF10A cells overexpressing TWIST or SNAI2. Figure S4. Western blot analysis of HIF-1Îą in MCF7 and MCF10A cells. Table S1. Gene expression correlation analysis, in cell lines. Table S2. Gene expression correlation analysis towards specific gene panels. Table S3. Lists of probes, antibodies, and dyes. (PDF 7335 kb)
Supplemental methods (PDF 26 kb)
Asian Pacific Journal of Cancer Prevention : APJCP, 2017
Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 whi... more Missense mutations in PIK3CA are common in breast cancers. They mostly involve exons 9 and 20 which encode kinase and helical domains of the protein and may result in its activation. PIK3CA activating mutations were previously shown to predict lower pathologic complete response (pCR) in HER2-positive breast cancer cases undergoing neoadjuvant human epidermal growth factor receptor 2-targeting therapy. Hence, the present work was conducted to estimate the mutation frequency in PIK3CA in 51 HER2-positive patients by direct sequencing. Our results showed 8 out of 51 (15.7%) to harbor PIK3CA mutations in either exon 9 or 20, or both. Three patients had mutations in both exons 9 and 20. Seven (13.7%) possess missense mutations in exon 20 which changed the amino acid sequence of the protein (H1047R, M1040I, and G1049G). Only four cases harbored mutations in exon 9, changing the codon sequences (E545K E545A, and R524K). Taking the clinicopathological data to account, the mutation frequency...
Biomarkers, 2021
Background: While large GWAS analyses have not found convincing associations between MDM2 promote... more Background: While large GWAS analyses have not found convincing associations between MDM2 promoter SNP55 and gynaecological cancers, SNP55 is in linkage disequilibrium with two other functional SNPs in the same promoter, likely to obscure associations between single SNPs and cancer risk. Here, we assessed the impact of SNP55 on risk of endometrial and ovarian cancer, including sub-analyses stratified for other functional SNPs in the region. Material and methods: Using a custom LightSNiP assay, we genotyped SNP55 in two large hospitalbased cohorts of patients with ovarian (n ¼ 1,332) and endometrial (n ¼ 1,363) cancer and compared genotypes to healthy female controls (n ¼ 1,858). Results: Among individuals harbouring the SNP309TT genotype, the minor SNP55T-allele was associated with a reduced risk of endometrial (dominant model: OR ¼ 0.63; CI ¼ 0.45-0.88; p ¼ 0.01). Regardless of the genotype in neighbouring SNPs, the SNP55T-allele was also associated with a reduced risk of endometrial cancer before 50 years of age (dominant model: OR ¼ 0.56; CI ¼ 0.34-0.90; p ¼ 0.02). No association between SNP55 status and ovarian cancer risk was observed. Conclusions: MDM2 SNP55T-allele may correlate with reduced risk for endometrial cancer in a SNP309T-, but not SNP309G, context.
Cancer & Metabolism, 2019
Background: Epithelial to mesenchymal transition (EMT) is a well-characterized process of cell pl... more Background: Epithelial to mesenchymal transition (EMT) is a well-characterized process of cell plasticity that may involve metabolic rewiring. In cancer, EMT is associated with malignant progression, tumor heterogeneity, and therapy resistance. In this study, we investigated the role of succinate dehydrogenase (SDH) as a potential key regulator of EMT. Methods: Associations between SDH subunits and EMT were explored in gene expression data from breast cancer patient cohorts, followed by in-depth studies of SDH suppression as a potential mediator of EMT in cultured cells. Results: We found an overall inverse association between EMT and the SDH subunit C (SDHC) when analyzing gene expression in breast tumors. This was particularly evident in carcinomas of basal-like molecular subtype compared to non-basal-like tumors, and a low SDHC expression level tended to have a prognostic impact in those patients. Studies in cultured cells revealed that EMT was induced by SDH inhibition through SDHC CRISPR/Cas9 knockdown or by the enzymatic inhibitor malonate. Conversely, overexpression of EMT-promoting transcription factors TWIST and SNAI2 caused decreased levels of SDHB and C and reduced rates of SDH-linked mitochondrial respiration. Cells overexpressing TWIST had reduced mitochondrial mass, and the organelles were thinner and more fragmented compared to controls. Conclusions: Our findings suggest that downregulation of SDHC promotes EMT and that this is accompanied by structural remodeling of the mitochondrial organelles. This may confer survival benefits upon exposure to hostile microenvironment including oxidative stress and hypoxia during cancer progression.
Indian Journal of Hematology and Blood Transfusion, 2017
Although the clinical features of isocitrate dehydrogenase (IDH) genetic aberrations have been we... more Although the clinical features of isocitrate dehydrogenase (IDH) genetic aberrations have been wellcharacterized in acute myeloid leukemia (AML), definitive information on their prognostic significance is lacking. We aimed to explore the prognostic significance of IDH gene alterations in an Egyptian cohort of adult patients with de novo AML. Diagnostic peripheral blood samples from 51 AML patients were analyzed for the presence of mutations/ SNPs in exon 4 of IDH1 and IDH2 genes using polymerase chain reaction amplification followed by direct sequencing. IDH mutational status had no impact on event-free survival (EFS) and overall survival (OS), whereas the presence of IDH1 315C[T SNP was significantly associated with inferior EFS (P = 0.037) and OS (P = 0.034) as compared with wild-type IDH1. IDH1 315C[T SNP but not IDH mutations is associated with unfavorable outcomes, suggesting that AML patients with IDH1 315C[T SNP can represent a new subgroup of patients which allows refined risk stratification.
Cellular Oncology, 2017
Background The ability of tumor cells to invade and metastasize is relevant to the process of can... more Background The ability of tumor cells to invade and metastasize is relevant to the process of cancer progression and, as such, it represents an obstacle to cancer cure. So far, limited information is available on interactions between circulating tumor cells and blood cells. It is well-documented that galectin-4 is upregulated in many types of tumor cells and is involved in metastasis. Here, we address the hypothesis that tumor cells may interact with red blood cells (RBCs) via galectin-4. Methods High galectin-4 expressing colon, normal pancreatic and pancreatic cancer-derived cell lines (n = 5) were incubated with peripheral blood cells from different donors. Their interactions and associated proteins were examined by immunostaining and live cell imaging. Results We found that (endogenous or exogenous) galectin-4 expressing tumor cells interact directly with RBCs. We also observed an accumulation of galectin-4 and human blood group antigens at the contact sites between these cells. By comparing the number of RBCs attaching to each tumor cell, we found that cells with high pre-incubation expression levels of galectin-4 attached significantly more RBCs than those with low expression levels (p < 1 × 10 −7). Conversely, we found that RBC attachment induces galectin-4 expression in tumor cells. Conclusions From our data we conclude that tumor cells directly interact with red blood cells via galectin-4.
Asian Pacific Journal of Cancer Prevention, 2015
The present study was conducted to investigate the effect of γ-radiation alone or combined with a... more The present study was conducted to investigate the effect of γ-radiation alone or combined with a cytotoxic drug, simvastatin, on viability and cell cycling of a myeloma cell line. P3NS1 myeloma cells were treated with the selected dose of simvastatin (0.1μM/l) 24 hours prior to γ-irradiation (0.25, 0.5 and 1Gy). The cell viability, induction of apoptosis, cell death, cell cycling, generation of ROS, and expression of P53, Bax, Bcl2, caspase3, PARP1 and Fas genes were estimated. The results indicated that simvastatin (0.1μM/l) treatment for 24 hours prior to γ-irradiation increased cell death to 37.5% as compared to 4.81% by radiation (0.5Gy) alone. It was found that simvastatin treatment before irradiation caused arrest of cells in G0/G1 and G2/M phases as assessed using flow cytometry. Interestingly, simvastatin treatment of P3NS1 cells increased the intracellular ROS production and decreased antioxidant enzyme activity with increased P53, Bax and Caspase3 gene expression while that of Bcl2 was decreased. Consequently, our results indicated that pre-treatment with simvastatin increased radio sensitivity of myeloma tumor cells in addition to apoptotic effects through an intrinsic mitochondrial pathway.