Null Genotype Research Articles

Clinical response of carboplatin-based chemotherapy and its association to genetic polymorphism in lung cancer patients from North India - A clinical pharmacogenomics study.

Lung cancer mostly diagnosed at advanced inoperable stages; thereby, the chemo-, radiation-, targeted or immune-therapy alone or in combination remains the treatment of choice. In chemotherapy, platinum-based compounds such as cisplatin and carboplatin and third-generation drugs such as docetaxel, paclitaxel, gemcitabine, and vinorelbine are widely used. The beneficial therapeutic outcome of the chemotherapy alone or in combination with radiation (chemoradiation) and/or development of drug resistance depends on the inter-individual genetic differences. Hence, this study was carried out to find gene biomarker that could be useful in the diagnosis of the disease and to predict the outcome of chemo/chemoradiation therapy in ethnic North Indian population. In this clinical study, lung cancer (n = 52) patients from North Indian population were recruited. All the patients were treated with carboplatin target area under curve-5 in combination with third-generation drugs (gemcitabine 1.2 mg/m2; paclitaxel 175 mg/m2; and etopside 100 mg/m2) and radiation therapy. The genomic DNA was isolated from the blood sample and performed polymerase chain reaction (PCR) and PCR-restriction fragment length polymorphism. We found hazard ratio to be significantly higher for XPDLys751Gln (hazard ratio [HR] =2.11, 95% confidence interval [CI]: 0.98-4.53, P = 0.056) and IL1 β511C/T (HR = 9.9, 95% CI: 2.55-38.40, P = 0.001). GSTT1 null (HR = 0.39, 95%CI: 0.18-0.84, P = 0.017) genotype has better response to chemotherapy. Generalized multidimensional reduction model suggested that IL1RN (cross-validation consistency [CVC] =10/10, P = 0.054) and XRCC1399Gln, GSTM1 (CVC = 10/10, P = 0.001) as best predicted model in lung cancer patients to the treatment response. Genetic polymorphisms and single nucleotide polymorphisms in DNA repair gene (XRCC1, XPD) and drug-metabolizing gene (GSTM1 and GSTT1) could serve as genetic biomarkers in lung cancer patients treated with the above indicated chemotherapy. Based on genotype and chemotherapy treatments, the toxicity effects can be minimized, this will help in the development of personalized medicine in future with better efficacy.

Role of Glutathione S-transferase Mu 1 and Glutathione S-transferases Theta 1 Polymorphism in the Risk of Developing Type 2 Diabetes Mellitus at Universitas Sumatera Utara Hospital, Medan

BACKGROUND: Diabetes mellitus is associated with an increased production of reactive oxygen species (ROS) and a reduction in antioxidant defense. Glutathione S-transferases (GSTs) is group of multifunction antioxidant enzyme can be used as important biomarkers for DM.. GSTM1, T1 genes variant polymorphism result in decreased or loss of enzyme activity.
 AIM: The study aimed to evaluate the role of GSTM1 and GSTT1 gene polymorphism in the risk of developing T2DM.
 METHODS: GSTM1 and GSTT1 polymorphisms were genotyped in 87 T2DM patients and 87 healthy control group to analyze their association with T2DM susceptibility by using multiplex Polymerase Chain Reaction (PCR). PCR products were electrophoresed using agarose 2%. Odds ratio (OR) with 95% confidence interval (CI) and P value were calculated using SPSS software (version 21.0).
 RESULTS: The genotype distribution of GSTM1 and GSTT1 were not different between T2DM patients and healthy control group (p = 0.542, OR= 0.780, CI 95%=0.350-1.737 and p=0.879, OR=1.047, CI 95%=0.577-1.903). The genotype distribution of combination of GSTM1 and GSTT1 were also not not different between T2DM patients and healthy control group (p = 0.640, OR= 0.640, CI 95%=0.224-1.83 and p=0.551, OR=0.721, CI 95%=0.245-2.120.
 CONCLUSION: In summary, this study showed that GSTT1 null, GSTM1 null, the combination of GSTM1 null and GSTT1 null genotype or combination of GSTM1 null and GSTT1 positive (or contrary) did not have any risk of developing T2DM at Universitas Sumatera Utara Hospital, Medan.

Influence of GSTM1, GSTT1, and GSTP1 genetic polymorphisms on disorders in transplant patients: a systematic review.

The glutathione-S-transferase (GST) enzymes are phase II isoenzymes responsible for protection against free radicals and xenobiotics. Since these proteins are described as polymorphic, polymorphisms in genes that encode them may alter enzymatic function and contribute to oxidative stress. In this context, such polymorphisms were already associated with several diseases and multiple therapeutic outcomes. A systematic review was performed to evaluate studies regarding the association between polymorphisms in three genes encoding enzymes of the GST family- GSTM1, GSTT1, and GSTP1- and disorders in transplant patients. A total of 125 articles on which inclusion and exclusion criteria were applied were identified at PubMed database. Thirty-two studies met the target criteria and were included in the review. The mechanisms by which GST genotypes influence the development of disorders in transplant patients differ by disorder: they may participate in it by decreasing metabolism of drugs administered to patients undergoing transplantation, then exposing them to greater toxicity; by decreasing the repair ability against oxidative stress; or by encoding proteins that may be recognized as foreign, setting of an alloimmune reaction. Although some results are better established- such as GSTM1 null genotype's role in the development of toxicity events in transplant patients- others require further evidences, as GST influence on the development of pulmonary decline and posttransplant diabetes mellitus (PTDM). The importance of investigating these associations lies in a personalized medicine, in which the high-risk genotype patient has its treatment individualized and its care for prophylaxis and surveillance increased, potentially reducing this population's morbimortality.

Features of GSTM1, GSTT1 and GSTP1 Genetic Polymorphism in Nizhny Tagil Metallurgical Plant Workers with Cardiovascular Diseases

Background: The development of cardiovascular diseases is determined not only by working conditions but also by genetic characteristics of employees. Genetic GSTM1, GSTT1 and GSTP1 variations contribute to individual differences in responses to industrial chemicals and carcinogens. Objective: To study the features of the genetic polymorphism of the GSTM1, GSTT1, and GSTP1 genes in metallurgical plant workers with diseases of the cardiovascular system in the town of Nizhny Tagil, Sverdlovsk Region, Russian Federation. Materials and methods: The case cohort included 61 men aged 33 to 61 years (mean: 48.15 ± 7.50 years), working in the converter shop and suffering from heart diseases. The control cohort consisted of 29 conditionally healthy male employees, aged 23–56, of the same iron and steel works having no signs of a cardiovascular disease. The DNA was isolated from peripheral blood using a standard technique. Deletion polymorphism of GSTM1 and GSTT1 genes was determined by quantitative PCR; Ile105Val polymorphism of the GSTP1 gene was established by qPCR using a commercial test kit. Results: We observed no statistically significant differences between the cohorts for any of the studied genes. The frequency of occurrence of the combination of GSTM1 (0/0) and GSTT1 (0/0) in the cases and controls was 14 % and 11 %, respectively, but the difference was negligible. Conclusions: Our findings demonstrate that the presence of null genotypes of GSTM1, GSTT1, as well as the mutant GSTP1 allele and the associated loss of enzyme activity contribute little to the development of cardiovascular diseases in workers exposed to occupational hazards.

The role of GSTM1 gene polymorphism in pathophysiology, evaluation, and management of constipation of anorectal outlet obstruction.

Constipation of anorectal outlet obstruction may be caused by mechanical or functional causes. This complication is a debilitating disease that needs proper and timely treatment. Many studies have shown that there is a direct link between constipation and intestinal cancer. One of the most effective ways to prevent or diagnose intestinal cancer is through genetic studies. Evaluation of people's polymorphism shows how much they are at risk for cancer. Therefore, in this study, the GSTM1 gene polymorphism was evaluated in patients with constipation of anorectal outlet obstruction to assess better and manage this disease and investigate the possibility of anorectal cancer in these people. In this regard, 40 people with constipation of anorectal outlet obstruction were compared with 40 healthy people. In the case group (patients), in addition to demographic and clinical evaluations, the anorectal manometric test was used to diagnose the pathology of the disease. Results showed that out of 40 patients with constipation of anorectal outlet obstruction, 5 cases (12.5%) had megarectum, 7 cases (17.5%) had anismus, 10 cases (25%) had Hirschsprung's disease, 5 cases (12.5%) had descending perineum syndrome, 6 cases (15%) had rectal prolapse, 4 cases (10%) had enterocele, and 3 cases (7.5%) were with rectocele. Also, the results of GSTM1 gene deletion polymorphism showed that patients with constipation of anorectal outlet obstruction were almost two times more exposed to the null genotype than the control group (P <0.04). Therefore, in people with both constipation of anorectal outlet obstruction and null genotype (i.e., deletion in the GSTM1 gene), because they do not have glutathione-S transferase, they appear to be at higher risk for anorectal cancer than healthy people with the same genotype.

PATH-11. PDGFA INITIATES ABERRANT MITOSIS AND MALIGNANT TRANSFORMATION OF NEURAL PROGENITOR CELLS

Abstract BACKGROUND Imagining ways to prevent or treat glioblastoma (GBM) have been hindered by a lack of understanding of its pathogenesis. Although platelet derived growth factor-A (PDGFA) overexpression may be an early event, critical details of the biology of GBM, and tools to study its initiation have been lacking. Indeed, many PDGF-driven models replicate its microscopic appearance, but not genomic architecture. Recently, we reported an in vitro model of GBM initiation that overcomes this barrier to authenticity. METHODS We used a method developed to establish neural stem cell cultures to investigate the effects of PDGF-A on cells derived from the subventricular zone (SVZ), a putative region where the cells of origins for GBM are derived. We micro-dissect SVZ tissue from p53-null and wild-type adult mice, culture cells in media supplemented with PDGF-A, and assess cell viability, proliferation, mitotic capacity, and genome stability. RESULTS Paradoxical to its canonical role as a growth factor, we observe abrupt and substantial cell death in PDGF-A. Abnormal mitosis was the first observable alteration and occurred immediately in cells of both p53 wild-type and null genotypes: wild-type cells did not survive in PDGF-A, whereas a fraction of null cells evade apoptosis. Evading cells displayed attenuated proliferation accompanied by early chromosomal gains and losses. After approximately 100 days in PDGF-A, surviving cells suddenly proliferate rapidly, acquire growth factor independence, and become tumorigenic in immune-competent mice. Transformed cells continue to display highly abnormal mitotic phenotypes with complex karyotypes similar to GBM, had a neural progenitor cell (NPC) lineage profile, and were resistant to PDGFR-alpha inhibition. CONCLUSION Abnormal mitosis induced by PDGF-A initiates and perpetuates the genome instability that transforms p53-null neural progenitor cells to yield cancers with the types of recurring chromosomal gains and losses that characterize human GBM.

FANCA Variants in Exons 27-30 Are Associated with Solid Tumors in Fanconi Anemia

Fanconi anemia (FA) is predominantly an autosomal recessive inherited bone marrow failure syndrome (IBMFS) characterized by congenital anomalies, bone marrow failure (BMF) and an increased cancer risk. It is caused by pathogenic variants in more than 22 genes in the FA/BRCA DNA repair pathway. Approximately 60% of patients have biallelic variants in FANCA. We sought to identify phenotypic differences and clinical outcomes of patients with diverse FANCA variants.We analyzed data from 86 patients with variants in FANCA enrolled in the National Cancer Institute (NCI) IBMFS study (ClinicalTrials.gov identifier 00027274). FANCA variants were determined through review of genetic test reports or whole exome sequencing done as part of the study. The variants were plotted using the online tool ProteinPaint (https://proteinpaint.stjude.org, Figure 1A). Clinical data were extracted from review of medical records and/or evaluations at the NIH.We compared patients with: 1) hypomorphic (hypomorphic variant on one or both alleles) versus null genotype (null variants on both alleles), 2) single nucleotide variant (SNV)/small insertions/deletions (indels) on both alleles versus SNV/small indels on one allele plus large multi-exon deletion on the other allele versus large multi-exon deletions on both alleles. We further compared patients with one or biallelic variants involving the BRCA1 interaction region in the N-terminal domain, FAAP20-binding domain, and variants in exons 27 to 30 where we saw an accumulation of variants, with patients who did not have variants in these regions. We evaluated physical abnormalities that are part of VACTERL-H (Vertebral, Anal, Cardiac, Tracheo-esophageal fistula, Esophageal or duodenal atresia, Renal, upper Limb abnormalities, Hydrocephalus) association and PHENOS (skin Pigmentation abnormalities, small Head, small Eyes, central Nervous system, Otologic abnormalities, Short stature). We focused on the presence, severity and age at BMF, and development of cancers and age at first solid tumor. Frequencies were compared by Fisher's exact test, and a multiple Cox regression model was used to estimate hazard ratio of solid tumors in patients with variants in different regions of FANCA, adjusting for age and hematopoietic cell transplant status of patients with cancer. Analyses were performed using Excel and RStudio, p-value <0.05 was considered significant.The phenotypes, BMF and cancer outcomes were similar between patients with hypomorphic and null genotypes. Similarly, comparison between patients with SNV/small indels, SNV/small indel plus large deletion, and biallelic large deletions did not reveal significant associations. Comparison according the location of the variants on FANCA protein showed that VACTERL-H and VACTERL-H plus PHENOS were less common in patients with at least one SNV/small indel in the BRCA1 interaction region of FANCA compared with patients without variants in this region (2/33 vs 12/51, p= 0.04; 1/33 vs 11/51, p= 0.024, respectively). These associations were not observed when we included patients with large deletions encompassing the BRCA1 interaction region.Eighteen of the 86 patients developed solid tumors; 15/45 patients with an SNV/small indel and/or large deletion within or including exons 27-30 region developed solid tumors compared with 3/41 patients without variants in this region (p= 0.003). Cox regression analysis showed that patients with variants within or involving exons 27-30 were at higher risk of developing solid tumors compared with those without variants in this region (HR: 6.2, 95% CI: 1.36-28.2, Figure 1B). There was no difference between the age at first cancer or type of solid tumors in patients with and without the variant involving this region. The frequency, severity, and age of BMF were also similar between the groups.Our data highlight the possibility that variants involving exons 27-30 within the C-terminal domain of FANCA may be associated with solid tumor development. FANCA forms a homodimer through the interaction between C-terminal domains; variants in this region may affect dimerization and further protein function. Functional analysis and in vivo studies of individual variants in this region and effects of the variants in trans might provide new insights into oncogenesis in FA and may have implications in personalized cancer screening. [Display omitted] DisclosuresNo relevant conflicts of interest to declare.

Evaluation of molecular markers GSTM1 and GSTT1 and clinical factors in breast cancer: case-control study and literature review

The study was conducted to evaluate the frequency of polymorphisms in GSTM1 and GSTT1 genes in patients with breast cancer compared with individuals without history of cancer, and the association of these polymorphisms with clinical/epidemiological parameters. There were evaluated 752 women (219 patients and 533 controls). Molecular analysis was performed by the Polymerase Chain Reaction (PCR). Statistical analysis was used multiple logistic regression and descriptive statistics. Age ≥ 50 years (OR = 3.22, 95% CI = 2.30–4.51, p < 0.001) and alcohol consumption (OR = 1.60, 95% CI = 1.13–2.27, p = 0.008) were associated to the development of breast cancer, while smoking and null genotypes GSTM1 and GSTT1 presented no association. GSTM1 and GSTT1 polymorphisms presented no relationship with the clinical and histopathological parameters or molecular subtypes of breast cancer. Ninety-two percent of tumours were invasive ductal, 66% were grade II, 65% were larger than 2 cm, the stages II (35.3%) and III (31.2%) were the most prevalent, and 47.7% were molecular subtype luminal B. Individuals aged ≥ 50 years and alcohol consumers have more chance to developing breast cancer. GSTM1 and GSTT1 polymorphisms are not associated to the risk of breast cancer.

Cytokinesis-block micronucleus cytome (CBMN-CYT) assay and its relationship with genetic polymorphisms in welders

Fumes generated in the welding process are composed of micrometric and nanometric particles that form when metal fumes condense. The International Agency for Research on Cancer established that many compounds derived from the welding process are carcinogenic to humans. Still, there are few studies related to the role of genetic polymorphisms. This work aimed to analyze the influence of OGG1 Ser326Cys, XRCC1 Arg280His, XRCC1 Arg194Thr, XRCC1 Arg399Gln, XRCC3 Thr241Met, GSTM1, and GSTT1 gene polymorphisms on DNA damage of 98 subjects occupationally exposed to welding fumes and 100 non exposed individuals. The results showed that individuals exposed to welding fumes with XRCC3 Thr241Thr, XRCC3 Thr241Met, and GSTM1 null genotypes demonstrated a significantly higher micronucleus frequency in lymphocytes. In contrast, individuals with XRCC1 Arg399Gln and XRCC1 Gln399Gln genotypes had significant levels of NPBs. OGG1 326 Ser/Cys, OGG1 326 Cys/Cys, XRCC1 194Arg/Thr, XRCC1 194Thr/Thr, and GSTT1 null genotypes exhibited significantly higher apoptotic values. Also, XRCC1 194Arg/Trp, XRCC1 194Thr/Thr, and GSTM1 null genotype carriers had higher necrotic levels compared to XRCC1 194Arg/Arg and GSTM1 nonnull carriers. Compositional analysis revealed the presence of iron, manganese, silicon as well as particles smaller than 2 μm that adhere to each other and form agglomerates. These results may be associated with a mixture of components, such as nitrogen dioxide, carbon monoxide, and metallic fumes, leading to significant DNA damage and cell death processes. These findings demonstrated the importance of the association between individual susceptibility and DNA damage levels due to occupational exposure to welding fumes; and constitute one of the first studies carried out in exposed workers from Colombia.

Glutathione S -transferase (M1 and T1) and angiotensin-converting enzyme gene polymorphisms and chronic kidney disease in Bangladeshi population

Chronic kidney disease (CKD) is a worldwide public health problem that affects a huge number of individuals and documented as a global public health problem. This study was conducted to uncover the association of gene polymorphism of Glutathione S -transferase M1 (GSTM1, rs366631), Glutathione S -transferase T1 (GSTT1, rs17856199), Angiotensin converting enzyme- Insertion/Deletion (ACE-I/D, rs4646994), and Cytochrome P450 Family 11 Subfamily B Member 2 − 344 T/C (CYP11B2 − 344 T/C, rs1799998) with the risk of development of CKD in Bangladeshi population. Blood samples were drawn from 355 participants (175 CKD patients and 180 healthy controls) by an expert phlebotomist. Different techniques like allele-specific multiplex PCR (Polymerase chain reaction), allele-specific PCR, and PCR-RFLP (Polymerase chain reaction-restriction fragment length polymorphism) were used for the genetic polymorphism analysis. Significant associations were evident for GSTT1 null genotype (OR = 2.45; 95% CI = 1.56–3.82; p < 0.001), combined GSTM1-GSTT1 null genotype (OR = 4.16; 95% CI = 1.99–8.64; p < 0.001) and homozygous mutant variant (DD) of ACE- I/D gene (OR = 4.60; 95% CI = 1.77–12.00; p < 0.01). Homozygous mutant variant (DD) of ACE- I/D polymorphism was found to be more prevalent in the male CKD subjects. It is apparent from our findings that the null genotype of GSTT1, combined GSTM1-GSTT1 null genotype, and homozygous mutant variant (DD) of ACE- I/D could be associated with CKD susceptibility.

Role of Glutathione-S-Transferase M1 (GSTM1) and T1 (GSTT1) Genes on Aluminum Concentration and Oxidative Markers among Autistic Children

Autism Spectrum Disorder (ASD) is considered a multifaceted neurodevelopmental disorder. The last two decades showed an increase in its prevalence until reached about 1 in 54 children. Autistic symptoms may be exacerbated when the interaction of the genetic and the environmental risk factors occur, suggesting that gene-environment interaction could be a mechanism underlying the etiology of ASD. Aluminum is a known neurotoxic metal that has known health effects in humans. Glutathione-S-transferase (GST) genes and their enzymes play a major role in the detoxification of many toxic metals.Data were collected from 76 children aged 2-8 years diagnosed with ASD and 30 sex and age matched healthy children. The aim of this study was to investigate the association of polymorphisms in the two GST genes (GSTM1 and GSTT1) with mean aluminum concentrations (as, gene-environment interaction) and oxidative status markers (GST enzyme, malondialdehyde and nitric oxide) among the studied groups. The study started at December 2019 and last for one year at the clinics of National Research Centre, Egypt.The results of this study showed that the null GSTM1 and GSTT1 genotype is the most common type in ASD and that genotype may predispose ASD children to decreased antioxidant status (GST enzyme activity) which in term lead to mal detoxification of aluminum. There is marked increase in aluminum concentrations in hair of ASD children and oxidative markers (increase in MDA and NO) leading to oxidative damage that may play an important role in children autistic status. The study recommends adding antioxidant supplements to daily diet of ASD children to improve their antioxidant status and in term improving management of patients with autism spectrum disorders. Further studies are needed to describe other GST gene polymorphisms.

GSTM1 and GSTT1 double null genotypes determining cell fate and proliferation as potential risk factors of relapse in children with hematological malignancies after hematopoietic stem cell transplantation

PurposeThis study aimed to retrospectively evaluate the genetic association of null variants of glutathione S-transferases GSTM1 and GSTT1 with relapse incidence in children with hematological malignancies (HMs) undergoing busulfan (BU)- containing allogeneic hematopoietic stem cell transplantation (HSCT) and to assess the impact of these variants on BU-induced cytotoxicity on the immortalized lymphoblastoid cell lines (LCLs) and tumor THP1 GST gene-edited cell models.MethodsGSTM1- and GSTT1-null alleles were genotyped using germline DNA from whole blood prior to a conditioning BU-based regimen. Association of GSTM1- and GSTT1-null variants with relapse incidence was analyzed using multivariable competing risk analysis. BU-induced cell death studies were conducted in GSTs- null and non-null LCLs and CRISPR–Cas9 gene-edited THP1 leukemia cell lines.ResultsCarrying GSTM1/GSTT1 double null genotype was found to be an independent risk factor for post-HSCT relapse in 86 children (adjusted HR: 6.52 [95% Cl, 2.76–15.42; p = 1.9 × 10–5]). BU-induced cell death preferentially in THP1GSTM1(non−null) and LCLsGSTM1(non−null) as shown by decreased viability, increased necrosis and levels of the oxidized form of glutathione compared to null cells, while GSTT1 non-null cells showed increased baseline proliferation.ConclusionThe clinical association suggests that GSTM1/GSTT1 double null genotype could serve as genetic stratification biomarker for the high risk of post-HSCT relapse. Functional studies have indicated that GSTM1 status modulates BU-induced cell death. On the other hand, GSTT1 is proposed to be involved in baseline cell proliferation.

Glutathione S-transferase gene polymorphisms in association with susceptibility to lead toxicity in lead- and cadmium-exposed children near an abandoned lead-zinc mining area in Kabwe, Zambia.

Interindividual genetic variations determine human's susceptibility to heavy metal-induced toxicity. Thus, we analyzed blood concentrations of lead (Pb) and cadmium (Cd) in 140 lead-exposed children. Genotyping of the glutathione S-transferase (GST) genes, GSTM1, GSTT1, and GSTP1 genes, was carried out to investigate their possible association with heavy metal concentrations and the risk of susceptibility to Pb toxicity. Exposure to both heavy metals was prevalent among the children. The blood Pb level ranged from 3.30 to 74.0 μg dL-1 with an average value of 26.8 μg dL-1 that is five times above its reference level. The average Cd level (0.22 μg L-1) was below its reference level. The metal-gene interaction showed positive correlation between GSTT1 null genotype and Pb and Cd levels (β = 0.11; p = 0.02 and β = 0.10; p = 0.01, respectively). More pronounced effects (β = 0.19; p < 0.01 and β = 0.25; p = 0.04) were found for the mixture of the three putative genes with blood Pb concentration. The susceptibility analysis using 10 μg dL-1 as blood Pb cutoff level showed a high risk of Pb toxicity (OR = 2.54; 95% CI: 1.02-6.32, p = 0.04) for children carrying the GSTP1 Ile/Val genotype. Further, the combined effect of GSTP1 Ile/Val with GSTT1 null genotype was more pronounced and showed an increased risk of susceptibility to Pb toxicity (OR = 11.7; 95% CI: 1.36-102.1, p = 0.02). In summary, this study suggests that GSTT1 null and GSTP1 Ile/Val genotypes are the main genetic factors, and individual and specific combinations of GSTP1 Ile/Val with GSTM1 and GSTT1 GST polymorphisms are associated with susceptibility to Pb toxicity.

Homozygous deletion of glutathione S-transferase theta 1 and mu 1 increase the risk of non-syndromic oral clefts in a Mexican population

ObjectiveTo investigate whether null variants of Glutathione S-transferase Mu 1 (GSTM1) and GST Theta 1 (GSTT1) in infants and mothers, as well as maternal exposures to environmental factors, contribute to the risk of non-syndromic cleft lip with or without palate (NSCL/P) in a Mexican population. DesignWe performed a matched pair case-control study, including 98 cases and 98 controls and their mothers. Sociodemographic information and environmental exposures were collected by a questionnaire. Null variants of GSTM1 and GSTT1 were assessed by multiplex Polymerase Chain Reaction (PCR). Odds ratios (OR) and their 95 % confidence intervals (CI) were calculated to estimate risks. The interaction of genetic variables with smoking and adjusted ORs were evaluated by binary logistic regression. ResultsHomozygous null GSTM1 was associated with the risk of NSCL/P when present in mothers (OR = 2.45, 95 % CI 1.23–4.86) or infants (OR = 2.98, 95 % CI 1.45–6.14). A higher risk was also found when children carried the homozygous null GSTT1 (OR = 4.89, 95 % CI 2.42–9.87). In mothers, this variant showed a crude risk of 9.17 (95 % CI 3.95–21.29), which increased to OR = 13.81 (95 % CI 1.63–117.09) upon interaction with frequent passive smoking (5–7 days/week). Sociodemographic and other environmental exposures were not significantly associated with the risk of NSCL/P. ConclusionsMaternal and infant GSTT1 and GSTM1 homozygous null genotypes were associated with a higher risk of NSCL/P, and the results suggest an interaction of the maternal GSTT1-null/null genotype with frequent passive smoking.

Low Adrenomedullary Function Predicts Acute Illness in Infants With Classical Congenital Adrenal Hyperplasia.

Youth with classical congenital adrenal hyperplasia (CAH) exhibit abnormal adrenomedullary function with decreased epinephrine levels noted in newborns and young infants. Little is known about how this relates to morbidity during the first year of life. This work aimed to study plasma epinephrine levels in infants with classical CAH and examine the clinical significance of epinephrine deficiency in the first year of life. This prospective cohort study comprised participants recruited from a pediatric tertiary care center: 36 infants with classical CAH due to 21-hydroxylase deficiency and 27 age-matched unaffected controls with congenital hypothyroidism. Main outcome measures included plasma epinephrine levels (N = 27), CYP21A2 genotype (N = 15), and incidence of acute illnesses from birth to age 1 year (N = 28). Epinephrine levels in CAH infants independently predicted illness incidence in the first year of life (β = -0.018, R = -0.45, P = .02) and were negatively correlated with 17-hydroxyprogesterone at diagnosis (R = -0.51, P = .007). Infants with salt-wasting CAH exhibited lower epinephrine levels as newborns than simple-virilizing infants (P = .02). CAH patients had lower epinephrine as newborns than did controls (P = .007) and showed decreases in epinephrine from birth to age 1 year (P = .04). Null genotype was associated with lower newborn epinephrine and more illness in the first year of life, compared to less severe mutation categories. Lower epinephrine levels are associated with increased risk of illness among CAH infants. While not currently part of clinical standard of care, measuring epinephrine levels and assessing genotype may help predict acute illness in the first year of life.

Relationship between GSTM1 and GSTT1 polymorphisms and HPV infection: a systematic review.

Human Papillomavirus (HPV) is the most important risk factor for cervical cancer, although not the only one. The allelic polymorphism of enzymes acting on carcinogen metabolism has shown to influence the risk of both intraepithelial lesions and cervical carcinogenesis. Several studies found an association between GSTM1/GSTT1 null genotypes and risk of cancer. This research aimed to review studies addressing the relationship between GSTT1 and GSTM1 and HPV infection in women, with or without cervical pathologies. A database search was conducted in four databases - PubMed, LILACS, SciELO, and Virtual Health Library - using the following descriptors: Glutathione transferase, HPV, and Genetic polymorphism. In total, we found 319 studies. After screening titles and abstracts, 27 articles were selected for full-text read, among which 20 were excluded and 7 were included in the review. No study has exclusively approached the relationship between the virus and GSTM1/GSTT1 variants. However, studies investigating the association between single nucleotide polymorphisms (SNPs) and cervical lesions or cancer found a probable relationship between them and infections with high-risk oncogenic subtypes. Although inconclusive, GSTT1 null alleles were more common in women with more aggressive HPV than GSTM1.

Frequency of glutathione S-Transferase M1, T1 and P1 genotypes and their combinations in northern West Bengal, India: Implications for disease association

Glutathione S-Transferases (GSTs) are important xenobiotic-detoxifying enzymes in animals. Polymorphisms in GST M1, GST T1, and GST P1 genes are common within human populations and have been linked to several multi-factorial diseases, including carcinogenesis. The present study aimed to determine the genotypic frequencies of M1, T1, and P1 in the healthy individuals (N = 332) of the northern region of West Bengal, India and to compare the frequencies with different populations studied elsewhere. Genotyping of the M1 and T1 alleles was performed using multiplex-PCR and the polymorphism of P1 allele was studied by PCR-RFLP using Alw261 restriction endonuclease. The M1 and T1 null genotypes were found in 34.9% and 27.4% individuals respectively and 9.9% of individuals were found to be double-null genotypes. The genotypic frequency of P1 revealed that 62.2% of individuals had wild type Ile/Ile genotypes, 29% were heterozygous Ile/Val and 8.7% individuals were homozygous Val/Val. There seemed to be no association between the presence of M1 and T1 alleles with any P1 genotypes (p < 0.05). While frequency of the M1 was found to be similar to most of the Indian populations, T1 was found to be different from other Indian populations. M1 and T1 frequencies are found to be similar to North-East Indian population but were higher than that found in other Indian populations. Given the importance of the alleles in detoxification of pesticides, drugs and carcinogenesis and the preponderance of null genotypes in human disease conditions, this study approaches to delineate demographic indicators that may help future investigations in pharmacological, clinical and genetic association studies.

Modifying Effect of Smoking on GSTM1 and NAT2 in Relation to the Risk of Bladder Cancer in Mongolian Population: A Case-Control Study.

Objectives:Tobacco smoking is the predominant risk factor for bladder cancer as it contains cancer-causing chemicals. However, genetic factors may play important role in response towards chemical carcinogens. In this study we aim to investigate genetic polymorphisms of glutathione S-transferase M1 (GSTM1) and N-acetyltransferase 2 (NAT2) as determinants of bladder cancer risk, independently and in combination with tobacco use in the Mongolian population. Materials and Methods:The current study was a hospital-based case-control study including 60 histologically confirmed bladder cancer patients and 60 cancer-free controls. PCR-RFLP assay was used to determine the presence of GSTM1 and NAT2 polymorphisms in bladder cancer patients and controls. GSTM1 and NAT2 were tested using binary logistical regression analysis with adjustment or stratification according to the smoking. Results:There were 46 men and 14 women diagnosed with bladder cancer, with mean age was 58±4. The controls included 37 men and 23 women with a mean age of 57±3. The frequency of GSTM1 null genotype was higher in controls (71.67%) than in bladder cancer patients (58.33%) without statistical significance (OR=0.5534; 95% CI=0.2586-1.1843), (p=0.128). The NAT2 low acetylator phenotype was more common in patients with bladder cancer (15%) than in controls (5%). Furthermore, individuals with NAT2 low acetylator phenotype had a nearly 3.35-fold increased risk to develop bladder cancer (OR=3.35; 95% CI=0.8604-13.0657), (p=0.081) while the risk was even higher when combined with null GSTM1 genotype (OR=4; 95% CI=0.4459-37.5308), (p=0.213) but there was no statistical significance. Prevalence of smoking in bladder cancer patients was higher than controls and increased significantly the risk of bladder cancer (OR=8.31; 95% CI=3.66-18.88). Smokers with GSTM1 null genotype were at 5-fold higher risk of bladder cancer (OR=5.0; 95% CI=1.55-16.16), (p=0.007) while NAT2 low acetylator phenotype increased bladder cancer risk by 20-fold (OR=20.5; 95% CI=2.33-80.86), (p=0.006). Conclusion:The current study shows that tobacco smokers with the NAT2 low acetylator phenotype and GSTM1 null genotype have the highest risk of bladder cancer in the Mongolian population.

The effects of genetic polymorphisms on benzene-exposed workers: A systematic review.

Background and AimsBenzene is a group I carcinogen, which has been associated with leukemia and myelodysplastic syndrome. Moreover, it has been proposed that polymorphisms in benzene metabolizing genes influence the outcomes of benzene exposure in the human body. This systematic review aims to elucidate the existent relationship between genetic polymorphisms and the risk of developing adverse health effects in benzene‐exposed workers.MethodsThree databases were systematically searched until April 2020. The preferred reporting items for systematic reviews and meta‐analyses method was used to select articles published between 2005 and 2020. Quality assessment and risk of bias were evaluated by the Newcastle‐Ottawa scale.ResultsAfter full‐text evaluation, 36 articles remained out of 645 initially screened. The most studied health effects within the reviewed papers were chronic benzene poisoning, hematotoxicity, altered urinary biomarkers of exposure, micronucleus/chromosomal aberrations, and gene methylation. Furthermore, some polymorphisms on NQO1, GSTT1, GSTM1, MPO, and CYP2E1, among other genes, showed a statistically significant relationship with an increased risk of developing at least one of these effects on benzene‐exposed workers. However, there was no consensus among the reviewed papers on which specific polymorphisms were the ones associated with the adverse health‐related outcomes, except for the NQO1 rs1800566 and the GSTT1 null genotypes. Additionally, the smoking habit was identified as a confounder, demonstrating worse health outcomes in exposed workers that smoked.ConclusionThough there is a positive relationship between genetic polymorphisms and detrimental health outcomes for benzene‐exposed workers, broader benzene‐exposed cohorts that take into account the genetic diversity of the population are needed in order to determine which specific polymorphisms incur in health risks.

Abstract 2937: Nedd9 controls autophagy to limit non-small cell lung cancer (NSCLC) growth

Abstract The goal of this study is to define the role of NEDD9 in formation of progression of non-small cell lung cancer (NSCLC). NSCLC has a low survival rate, with metastasis contributing to the vast majority of deaths. NEDD9 expression has been shown to be repressed by LKB1, and upregulated in LKB1-mutated NSCLC; in these tumors, elevated NEDD9 promotes metastasis, serving as a scaffolding intermediate in the integrin and receptor tyrosine kinase signaling cascades, promoting pro-invasive signaling. In this study, we for the first time assessed the consequences for cancer formation after introduction of a constitutive null allele of Nedd9 (KPN mice) in the Krastm4Tyj/J/Trp53tm1Brn/J (KP mice) Adeno-cre inducible murine model of NSCLC, in the context of intact Lkb1. Unexpectedly, KPN mice presented with significantly accelerated NSCLC tumorigenesis and enhanced tumor invasion. Orthotopic re-implantation of KP and KPN tumor into syngeneic mice with wt and null Nedd9 genotypes demonstrated that the effect of Nedd9 loss on promoting tumor growth is cell-autonomous. Proteomic analysis of KPN versus KP tumors revealed that more aggressive phenotypes occurred in spite of depressed activity of the pro-proliferative, pro-invasive Nedd9 partner proteins Src and Fak. Treatment of mice with the Src inhibitor dasatinib significantly reduced, but did not eliminate, tumor growth in KP and KPN mice. As an alternative hypothesis, we considered that Ras-dependent NSCLC tumors require active autophagy, a process dependent on activation of the kinases Lkb1 and Ampk; given Lkb1 represses Nedd9, we investigated whether Nedd9 reciprocally regulates Lkb1. We found that KPN tumors specifically and significantly upregulated active Lkb1 based on a mechanism of post-transcriptional activation, causing increased expression of the Lkb1 substrate Ampk and downstream effectors of autophagy, including elevated appearance of LC3-positive autophagosomes in KPN NSCLC tumor tissue. NEDD9 depletion in human NSCLC cell lines similarly elevated LKB1 activation. In vivo treatment of KPN and KP mice with the autophagy inhibitor chloroquine completely eliminated the growth advantage of KPN tumors, emphasizing the importance of autophagy for the growth differential. In sum, these data for the first time identify and define a previously unknown role for the pro-metastatic protein NEDD9 in control of autophagy, based on a role as a negative regulator of the Lkb1-Ampk signaling axis in NSCLC. Citation Format: Alexander Y. Deneka, Meghan Kopp, Anna S. Nikonova, Anna Gaponova, Anna Kiseleva, Douglas Flieder, Ilya Serebriiskii, Harvey Hensley, Erica Golemis. Nedd9 controls autophagy to limit non-small cell lung cancer (NSCLC) growth [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 2937.