Prevalence and clinical implications of germline pathogenic variants in cancer predisposing genes in young patients across sarcoma subtypes.

BACKGROUND: Sarcomas are a rare and diverse group of cancers occurring mainly in young individuals for which an underlying germline genetic cause remains unclear in most cases. METHODS: Germline DNA from 177 children, adolescents and young adults with soft tissue or bone sarcomas was tested using multigene panels with 113 or 126 cancer predisposing genes (CPGs) to describe the prevalence of germline pathogenic/likely pathogenic variants (GPVs). Subsequent testing of a subset of tumours for loss of heterozygosity (LOH) evaluation was performed to investigate the clinical and molecular significance of these variants. RESULTS: GPVs were detected in 21.5% (38/177) of the patients (15.8% in children and 21.6% in adolescents and young adults), with dominant CPGs being altered in 15.2% overall. These variants were found in genes previously associated with the risk of developing sarcomas (TP53, RB1, NF1, EXT1/2) but also in genes where that risk is still emerging/limited (ERCC2, TSC2 and BRCA2) or unknown (PALB2, RAD50, FANCM and others). The detection rates of GPVs varied from 0% to 33% across sarcoma subtypes and GPV carriers were more likely to present more than one primary tumour than non-carriers (21.1%×6.5%; p=0.012). Loss of the wild-type allele was detected in 48% of tumours from GPV carriers, mostly in genes definitively associated with sarcoma risk. CONCLUSION: Our findings reveal that a high proportion of young patients with sarcomas presented a GPV in a CPG, underscoring the urgency of establishing appropriate genetic screening strategies for these individuals and their families.

Germline pathogenic variants in patients with early-onset neuroendocrine neoplasms.

Neuroendocrine neoplasms (NENs) are a rare group of cancers with heterogeneous behaviour and mostly of unknown aetiology. Excluding some infrequent hereditary cancer syndromes, the extent and clinical significance of mutations in other cancer predisposing genes (CPGs) are not known. We aimed to investigate the frequency of pathogenic and likely germline pathogenic variants (GPVs) in known CPGs in young adults with NEN and the clinical and molecular characteristics of these patients. We recruited 108 patients with lung or digestive NEN diagnosed between 18 and 50 years and performed targeted sequencing of 113 CPGs on germline DNA. For some patients, tumour features such as loss of heterozygosity (LOH), tumour mutation burden and microsatellite instability were evaluated. GPVs were detected in 17 patients (15.7%). Median age, sex, stage at diagnosis, family history of NENs or any personal history of neoplasm were similar between patients with or without GPVs. GPV carriers had more gastric (P = 0.084), functioning NEN (P = 0.041), positive family history of cancer (P = 0.015) and exclusively well-differentiated histology. Genes affected were mostly involved in DNA repair (CHEK2, ERCC2, ERCC3, XPC, MSH6, POLE and SLX4), with most GPVs found in MUTYH (four cases). LOH was performed in eight tumours and detected only in an SLX4-positive case. Overall, our findings indicate a role of inherited genetic alterations, particularly in DNA repair genes, in NEN carcinogenesis in young adults. These patients more often had a family history of cancer and functioning NENs.

A case-control study of a combination of single nucleotide polymorphisms and clinical parameters to predict clinically relevant toxicity associated with fluoropyrimidine and platinum-based chemotherapy in gastric cancer.

BACKGROUND: Fluoropyrimidine plus platinum chemotherapy remains the standard first line treatment for gastric cancer (GC). Guidelines exist for the clinical interpretation of four DPYD genotypes related to severe fluoropyrimidine toxicity within European populations. However, the frequency of these single nucleotide polymorphisms (SNPs) in the Latin American population is low (< 0.7%). No guidelines have been development for platinum. Herein, we present association between clinical factors and common SNPs in the development of grade 3-4 toxicity. METHODS: Retrospectively, 224 clinical records of GC patient were screened, of which 93 patients were incorporated into the study. Eleven SNPs with minor allelic frequency above 5% in GSTP1, ERCC2, ERCC1, TP53, UMPS, SHMT1, MTHFR, ABCC2 and DPYD were assessed. Association between patient clinical characteristics and toxicity was estimated using logistic regression models and classification algorithms. RESULTS: Reported grade ≤ 2 and 3-4 toxicities were 64.6% (61/93) and 34.4% (32/93) respectively. Selected DPYD SNPs were associated with higher toxicity (rs1801265; OR = 4.20; 95% CI = 1.70-10.95, p = 0.002), while others displayed a trend towards lower toxicity (rs1801159; OR = 0.45; 95% CI = 0.19-1.08; p = 0.071). Combination of paired SNPs demonstrated significant associations in DPYD (rs1801265), UMPS (rs1801019), ABCC2 (rs717620) and SHMT1 (rs1979277). Using multivariate logistic regression that combined age, sex, peri-operative chemotherapy, 5-FU regimen, the binary combination of the SNPs DPYD (rs1801265) + ABCC2 (rs717620), and DPYD (rs1801159) displayed the best predictive performance. A nomogram was constructed to assess the risk of developing overall toxicity. CONCLUSION: Pending further validation, this model could predict chemotherapy associated toxicity and improve GC patient quality of life.

COL4A1, negatively regulated by XPD and miR-29a-3p, promotes cell proliferation, migration, invasion and epithelial-mesenchymal transition in liver cancer cells.

OBJECTIVE: Collagen type IV alpha 1 (COL4A1) exerts tumor-promoting functions in several tumors. However, its role in liver cancer remains not fully understood. Hence, this study aims to investigate the role of COL4A1 in regulating liver cancer cell behaviors and to validate its upstream regulatory mechanism. METHODS: Expression of xeroderma pigmentosum D (XPD) and COL4A1 was examined by qRT-PCR and western blot. Cell proliferation, migration, and invasion were evaluated. The protein levels of N-cadherin, vimentin, and E-cadherin were determined by western blot to evaluate epithelial-mesenchymal transition (EMT). The interaction between miR-29a-3p and COL4A1 was analyzed by luciferase reporter assay. RESULTS: COL4A1 overexpression significantly promoted cell proliferation, migration, invasion, and EMT in Hep3B cells. In contrast, COL4A1 silencing yielded the opposite effects in HepG2 cells. Expression of COL4A1 was increased, whereas expression of XPD and miR-29a-3p was decreased in HCC tissues compared to controls. COL4A1 mRNA level was negatively correlated with expression of XPD and miR-29a-3p in HCC tissues. Furthermore, XPD silencing-mediated up-regulation of COL4A1 expression was attenuated by miR-29a-3p mimic. Moreover, miR-29a-3p mimic inhibited Hep3B cell proliferation, migration, and invasion by directly targeting COL4A1. CONCLUSION: COL4A1 is negatively regulated by XPD-miR-29a-3p axis and promotes liver cancer progression in vitro.

Comprehensive germline mutation analysis and clinical profile in a large cohort of Brazilian xeroderma pigmentosum patients.

BACKGROUND: Xeroderma pigmentosum (XP) patients present a high risk of developing skin cancer and other complications at an early age. This disease is characterized by mutations in the genes related to the DNA repair system. OBJECTIVES: To describe the clinical and molecular findings in a cohort of 32 Brazilian individuals who received a clinical diagnosis of XP. METHODS: Twenty-seven families were screened for germline variants in eight XP-related genes. RESULTS: All patients (N = 32) were diagnosed with bi-allelic germline pathogenic or potentially pathogenic variants, including nine variants previously undescribed. The c.2251-1G>C XPC pathogenic variant, reported as the founder mutation in Comorian and Pakistani patients, was observed in 15 cases in homozygous or compound heterozygous. Seven homozygous patients for POLH/XPV variants developed their symptoms by an average age of 7.7 years. ERCC2/XPD, DDB2/XPE and ERCC5/XPG variants were found in a few patients. Aside from melanoma and non-melanoma skin tumours, a set of patients developed skin sebaceous carcinoma, leiomyosarcoma, angiosarcoma, mucoepidermoid carcinoma, gastric adenocarcinoma and serous ovarian carcinoma. CONCLUSIONS: We reported a high frequency of XPC variants in 32 XP Brazilian patients. Nine new variants in XP-related genes, unexpected non-skin cancer lesions and an anticipation of the clinical manifestation in POLH/XPV cases were also described.

Association between Single Nucleotide Polymorphisms and Glioma Risk: A Systematic Literature Review.

This study aimed to determine the main single nucleotide polymorphisms (SNPs) that are associated with an increased or decreased risk of glioma development in healthy individuals. We conducted a systematic review of the articles published in English on the PUBMED database between January 2008 and December 2017. Our search resulted in a total of 743 articles; however, only 56 were included in this review. A total of 148 polymorphisms were found, which involved 64 different genes. The polymorphisms that were most associated with an increased risk of glioma development were polymorphic variants rs179782, rs13181, and rs3791679 of the genes XRCC1, ERCC2, and EFEMP1, respectively.

XPD/ERCC2 mutations interfere in cellular responses to oxidative stress.

Nucleotide excision repair (NER) is a conserved, flexible mechanism responsible for the removal of bulky, helix-distorting DNA lesions, like ultraviolet damage or cisplatin adducts, but its role in the repair of lesions generated by oxidative stress is still not clear. The helicase XPD/ERCC2, one of the two helicases of the transcription complex IIH, together with XPB, participates both in NER and in RNA pol II-driven transcription. In this work, we investigated the responses of distinct XPD-mutated cell lines to the oxidative stress generated by photoactivated methylene blue (MB) and KBrO3 treatments. The studied cells are derived from patients with XPD mutations but expressing different clinical phenotypes, including xeroderma pigmentosum (XP), XP and Cockayne syndrome (XP-D/CS) and trichothiodystrophy (TTD). We show by different approaches that all XPD-mutated cell lines tested were sensitive to oxidative stress, with those from TTD patients being the most sensitive. Host cell reactivation (HCR) assays showed that XP-D/CS and TTD cells have severely impaired repair capacity of oxidised lesions in plasmid DNA, and alkaline comet assays demonstrated the induction of significantly higher amounts of DNA strand breaks after treatment with photoactivated MB in these cells compared to wild-type cells. All XPD-mutated cells presented strong S/G2 arrest and persistent γ-H2AX staining after photoactivated MB treatment. Taken together, these results indicate that XPD participates in the repair of lesions induced by the redox process, and that XPD mutations lead to differences in the response to oxidatively induced damage.

Low-power laser alters mRNA levels from DNA repair genes in acute lung injury induced by sepsis in Wistar rats.

Acute lung injury (ALI) is defined as respiratory failure syndrome, in which the pathogenesis could occur from sepsis making it a life-threatening disease by uncontrolled hyperinflammatory responses. A possible treatment for ALI is the use of low-power infrared lasers (LPIL), whose therapeutical effects depend on wavelength, power, fluence, and emission mode. The evaluation mRNA levels of repair gene related to oxidative damage after exposure to LPIL could provide important information about the modulation of genes as treatment for ALI. Thus, the aim of this study was to evaluate the mRNA levels from OGG1, APEX1, ERCC2, and ERCC1 genes in lung tissue from Wistar rats affected by ALI and after exposure to LPIL (808 nm; 100 mW). Adult male Wistar rats (n = 30) were randomized into six groups (n = 5, for each group): control, 10 J/cm2 (2 J), 20 J/cm2 (5 J), ALI, ALI + LPIL 10 J/cm2 and ALI + LPIL 20 J/cm2. ALI was induced by intraperitoneal E. coli lipopolysaccharide injection (10 mg/kg). Lungs were removed, and samples were withdrawn for total RNA extraction, cDNA synthesis, and mRNA levels were evaluated by RT-qPCR. Data normality was verified by Kolmogorov-Smirnov, comparisons among groups were by Student's t test, Mann-Whitney test, one-way ANOVA, Kruskal-Wallis followed by post-tests. Data showed that OGG1 (0.39 ± 0.10), ERCC2 (0.67 ± 0.24), and ERCC1 (0.60 ± 0.19) mRNA levels are reduced in ALI group when compared with the control group (1.00 ± 0.07, 1.03 ± 0.25, 1.01 ± 0.16, respectively) and, after LPIL, mRNA relative levels from DNA repair genes are altered when compared to non-exposed ALI group. Our research shows that ALI alter mRNA levels from genes related to base and nucleotide excision repair genes, suggesting that DNA repair is part of cell response to sepsis, and that photobiomodulation could modulate the mRNA levels from these genes in lung tissue.

PIBIDS syndrome in two Brazilian siblings.

Trichothiodystrophy is a rare condition associated with autosomal recessive or X-linked dominant variants in the ERCC2, ERCC3, GTF2H5, MPLKIP, RNF113A or GTF2E2 genes. The genes associated to photosensitive trichothiodystrophy encode subunits of transcription factor IIH, involved in the nucleotide excision repair pathway. The disease is characterised by cysteine-deficient brittle hair along with other neuroectodermal abnormalities. It has a variable clinical expression and some cases might be associated with photosensitivity, resulting in the acronym PIBIDS (photosensitivity, ichthyosis, brittle hair, intellectual impairment, decreased fertility and short stature). We report clinical findings of two siblings diagnosed with trichothiodystrophy associated with marked photosensitivity.

New polymorphisms of Xeroderma Pigmentosum DNA repair genes in myelodysplastic syndrome.

The association between Xeroderma Pigmentosum DNA repair genes (XPA rs1800975, XPC rs2228000, XPD rs1799793 and XPF rs1800067) polymorphisms and myelodysplastic syndrome (MDS) have not been reported. To assess the functional role between these polymorphisms and MDS, we evaluated 189 samples stratified in two groups: 95 bone marrow samples from MDS patients and 94 from healthy elderly volunteers used as controls. Genotypes for all polymorphisms were identified in DNA samples in an allelic discrimination experiment by real-time polymerase chain reaction (qPCR). We also studied the mRNA expression of XPA and XPC genes to evaluate if its polymorphisms were functional in 53 RNAm MDS patients by qPCR methodologies. To the rs2228000 polymorphism, the CT and TT polymorphic genotype were associated with increased odds ratio (OR) of more profound cytopenia (hemoglobin and neutrophils count). To the rs1799793 polymorphism, we found that the GG homozygous wild-type genotype was associated with a decreased chance of developing MDS. We observed low expression of XPA in younger patients, in hypoplastic MDS and patients with abnormal karyotype when presented AG or AA polymorphic genotypes. We also found that there was a statistically significant interaction between the presence of micromegakaryocyte on down regulation of XPC regarding the CT heterozygous genotype of the rs1800975 polymorphism. Our results suggest that new functional polymorphisms of Xeroderma Pigmentosum DNA repair genes in MDS are related to its pathogenesis and prognosis.

XPD c.934G>A polymorphism of nucleotide excision repair pathway in outcome of head and neck squamous cell carcinoma patients treated with cisplatin chemoradiation.

This study aimed to investigate the associations of XPC c.2815A>C, XPD c.934G>A and c.2251A>C, XPF c.2505T>C and ERCC1 c.354C>T single nucleotide polymorphisms (SNPs) of nucleotide excision repair pathway in outcome of head and neck squamous cell carcinoma (HNSCC) patients treated with cisplatin (CDDP) chemoradiation. Patients with XPC c.2815AC or CC and XPD c.934GA or AA genotypes had 0.20 and 0.38 less chances of presenting moderate/severe ototoxicity and nausea, respectively. Patients with XPD c.934AA and c.2251AC or CC genotypes had 8.64, 12.29 and 3.55 more chances of achieving complete response (CR), consistent ototoxicity and nephrotoxicity, respectively. AA haplotype of XPD and ACT haplotype of XPD and ERCC1 SNPs were associated with 9.30 and 3.41 more chances of achieving CR and consistent nephrotoxicity, respectively. At 24 months of follow-up, patients with XPD c.934AA genotype presented lower progression-free survival and overall survival in Kaplan-Meier estimates, and differences between groups remained the same in univariate Cox analysis. Patients with XPD c.934AA genotype had 2.13 and 2.04 more risks of presenting tumor progression and death than others in multivariate Cox analysis. Our data present preliminary evidence that XPC c.2815A>C, XPD c.934G>A and c.2251A>C, and ERCC1 c.354C>T SNPs alter outcome of HNSCC patients treated with CDDP chemoradiation.

Correlation between gene polymorphisms of CYP1A1, GSTP1, ERCC2, XRCC1, and XRCC3 and susceptibility to lung cancer.

Lung cancer is a common malignant tumor that is characterized by high morbidity and poor prognosis. Studies suggest that an individual's genetic background affects the risk of developing lung cancer. Therefore, we investigated the relationship between gene polymorphisms and susceptibility to lung cancer. We recruited 308 primary lung cancer patients as subjects and 253 healthy adults as controls. After extraction of DNA from blood samples, gene polymorphisms in CYP1A1, GSTP1, ERCC2, XRCC1, and XRCC3 were investigated by polymerase chain reaction and restriction fragment length polymorphism. The frequencies of the genotypes in both groups were investigated to obtain odds ratios and 95% confidence intervals, and correlation analysis was carried out. The analysis results showed that the following polymorphisms were correlated with susceptibility to lung cancer: rs4646903 in CYP1A1 (P < 0.001), rs1048943 in CYP1A1 (P < 0.001), rs1695 in GSTP1 (P < 0.05), rs13181 in ERCC2 (P < 0.001), and rs25487 in XRCC1 (P < 0.05); no such correlation existed in rs861539 in XRCC3 (P > 0.05). The study revealed that the more high-risk gene polymorphisms a patient carries, the greater the risk of developing lung cancer. Carriers of rs4646903 in CYP1A1, rs1048943 in CYP1A1, rs1695 in GSTP1, rs13181 in ERCC2, and rs25487 in XRCC1 are more likely to develop lung cancer.

ERCC2 rs13181 polymorphism association with glioma susceptibility in a Chinese population.

We conducted a case-control study to investigate the role of ERCC2 rs13181 polymorphism in glioma development. A total of 165 patients who were histopathologically diagnosed to have gliomas and 330 controls were collected at Jiujiang First People's Hospital between July 2012 and June 2014. The ERCC2 rs13181 polymorphism was analyzed using a polymerase chain reaction -restriction fragment length polymorphism assay. By conditional regression analysis, we found that the GG genotype of the ERCC2 rs13181 polymorphism is associated with susceptibility to gliomas when compared to the TT genotype (OR = 2.05, 95%CI = 1.11-3.79). In the recessive model, the GG genotype is associated with an increased risk of gliomas when compared with the TT+TG genotype (OR = 1.87, 95%CI = 1.03-3.37). In conclusion, the ERCC2 rs13181 polymorphism is correlated with an increased risk of gliomas in codominant and recessive models, which suggests that this polymorphism could influence the etiology of gliomas.

Genetic variability of ERCC1 and ERCC2 genes involved in the nucleotide excision repair pathway influences the treatment outcome of gastric cancer.

We conducted a prospective study to investigate whether ERCC1 rs11615 and rs3212986 and ERCC2 rs13181 and rs1799793 gene polymorphisms could serve as potential biomarkers for the prognosis of gastric cancer. Between January 2010 and December 2012, 246 patients with pathologically proven gastric cancer who were receiving platinum-based chemotherapy were recruited from the First Affiliated Hospital of Guangxi Medical University. The genotyping of the gene polymorphisms was conducted using the polymerase chain reaction coupled with restriction fragment length polymorphism. By logistic regression analysis, we found that the AA genotype of ERCC1 rs3212986 was associated with lower rates of complete remission and partial remission following chemotherapy in gastric cancer patients, and the OR (95%CI) was 0.19 (0.06-0.60). We found that the AA genotype of rs3212986 was correlated with higher risk of death from gastric cancer according to the Cox proportional hazards model, and the adjusted HR (95%CI) was 1.60 (0.81-3.16). However, we found no association between ERCC1 rs11615, ERCC2 rs13181, and ERCC2 rs1799793 and overall survival of gastric cancer. In conclusion, the results of the present retrospective study indicate that the ERCC1 rs3212986 gene polymorphism has a significant effect on the pharmacokinetics and treatment outcome of gastric cancer.

Role of single nucleotide polymorphisms of DNA repair genes in susceptibility to pancreatic cancer in Chinese population.

We conducted a case-control study to investigate the role of ERCC1-ERCC5 gene polymorphisms in the risk of pancreatic cancer. This study included 195 patients who were newly diagnosed with histopathologically confirmed primary pancreatic cancer, and 254 controls were recruited from Sir Run Run Shaw Hospital, between January 2012 and December 2014. Genotyping of ERCC1 rs3212986 and rs11615, ERCC2 rs13181, ERCC3 rs4150441, ERCC4 rs6498486, and ERCC5 rs2094258 polymorphisms was carried out using polymerase chain reaction coupled with restriction fragment length polymorphism. Unconditional logistic regression analyses showed that the TT genotype of ERCC1 rs3212986 was associated with an increased risk of pancreatic cancer, and the OR (95%CI) was 2.26 (1.21-4.22). However, we did not find a significant association between ERCC1 rs11615, ERCC2 rs13181, ERCC3 rs4150441, ERCC4 rs6498486, and ERCC5 rs2094258 polymorphisms and risk of pancreatic cancer. In summary, we found that the presence of the ERCC1 rs3212986 polymorphism correlated with an increased risk of pancreatic cancer.

Role of ERCC2 and ERCC3 gene polymorphisms in the development of osteosarcoma.

We conducted a case-control study to investigate the role of common SNPs in ERCC2 (rs13181 and rs1799793) and ERCC3 (rs4150441 and rs4150506) in the development of osteosarcoma. A 1:2 matched case-control study was conducted. Between January 2012 and December 2013, 141 patients with pathologically diagnosed osteosarcoma and 282 controls were recruited in our study. Genotyping of ERCC2 rs13181 and rs1799793 as well as ERCC3 rs4150441 and rs4150506 were performed using polymerase chain reaction coupled with restriction fragment length polymorphism. The genotype distributions of ERCC2 rs13181 and rs1799793 as well as ERCC3 rs4150441 and rs4150506 showed no significant difference between patients with osteosarcoma and controls, as analyzed by c2 tests. Multivariate logistic regression analysis did not reveal significant associations between ERCC2 rs13181/rs1799793 or ERCC3 rs4150441/ rs4150506 gene polymorphisms and the development of osteosarcoma in codominant, dominant, and recessive models. In conclusion, we did not find any association between ERCC2 or ERCC3 gene polymorphisms and the development of osteosarcoma. Future studies with larger sample sizes may contribute in elucidating the impact of ERCC2 and ERCC3 gene polymorphisms on osteosarcoma risks.

Association between ERCC1 and ERCC2 gene polymorphisms and susceptibility to pancreatic cancer.

We conducted a study to investigate the association between ERCC1 (rs3212986) and ERCC2 (rs13181) gene polymorphisms and the risk of pancreatic cancer in a Chinese population. A total of 217 pancreatic cancer patients and 244 control subjects were recruited from the Nuclear Industry 215 Hospital of Shaanxi Province between February 2013 and December 2014. Genomic DNA was extracted from peripheral blood samples using a TIANamp Blood DNA Kit (Tiangen, Beijing, China) according to the manufacturer's instructions. The ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms were genotyped by polymerase chain reaction-restriction fragment length of polymorphism. Unconditional logistic regression analyses showed that subjects with the CC genotype of ERCC1 rs3212986 were susceptible to the development of pancreatic cancer when compared with subjects with the AA genotype (OR = 2.57, 95%CI = 1.34-5.02). The ERCC1 rs3212986 gene polymorphism was associated with increased risk of pancreatic cancer in the dominant (OR = 1.54, 95%CI = 1.05-2.28) and recessive (OR = 2.22, 95%CI = 1.20-4.19) models. However, no significant difference was found between the ERCC2 rs13181 polymorphism and the risk of pancreatic cancer in the codominant, dominant, and recessive models. We suggest that the ERCC1 rs3212986 polymorphism increases susceptibility to pancreatic cancer in the codominant, dominant, and recessive models, although further studies are needed to confirm our findings.

Association between ERCC1 and ERCC2 polymorphisms and breast cancer risk in a Chinese population.

We conducted a case-control study to investigate the role of ERCC1 rs3212986 and ERCC2 rs13181 gene polymorphisms in the development of breast cancer. Between March 2012 and March 2014, a total of 242 newly diagnosed breast cancer patients with histopathologically confirmed primary breast cancer and 242 healthy controls were recruited. Genotyping of ERCC1 rs3212986 and ERCC2 rs13181 polymorphisms was carried out using polymerase chain reaction-restriction fragment length polymorphism analysis. Unconditional logistic regression analyses indicated that the TT genotype of rs3212986 was associated with a higher risk of breast cancer compared to that associated with the GG genotype (OR = 2.05, 95%CI = 1.13-3.78). In dominant and recessive models, we found that the rs3212986 polymorphism was associated with increased risk of breast cancer, and the ORs were 1.50 (95%CI = 1.03-2.18) and 1.74 (95%CI = 1.01-3.11), respectively. In summary, we found that the ERCC1 rs3212986 polymorphism was associated with the development of breast cancer.

Low-intensity red and infrared lasers affect mRNA expression of DNA nucleotide excision repair in skin and muscle tissue.

Lasers emit light beams with specific characteristics, in which wavelength, frequency, power, fluence, and emission mode properties determine the photophysical, photochemical, and photobiological responses. Low-intensity lasers could induce free radical generation in biological tissues and cause alterations in macromolecules, such as DNA. Thus, the aim of this work was to evaluate excision repair cross-complementing group 1 (ERCC1) and excision repair cross-complementing group 2 (ERCC2) messenger RNA (mRNA) expression in biological tissues exposed to low-intensity lasers. Wistar rat (n = 28, 4 for each group) skin and muscle were exposed to low-intensity red (660 nm) and near-infrared (880 nm) lasers at different fluences (25, 50, and 100 J/cm(2)), and samples of these tissues were withdrawn for RNA extraction, cDNA synthesis, and gene expression evaluation by quantitative polymerase chain reaction. Laser exposure was in continuous wave and power of 100 mW. Data show that ERCC1 and ERCC2 mRNA expressions decrease in skin (p < 0.001) exposed to near-infrared laser, but increase in muscle tissue (p < 0.001). ERCC1 mRNA expression does not alter (p > 0.05), but ERCC2 mRNA expression decreases in skin (p < 0.001) and increases in muscle tissue (p < 0.001) exposed to red laser. Our results show that ERCC1 and ERCC2 mRNA expression is differently altered in skin and muscle tissue exposed to low-intensity lasers depending on wavelengths and fluences used in therapeutic protocols.

Association of the XPD and XRCC3 gene polymorphisms with oral squamous cell carcinoma in a Northeastern Brazilian population: A pilot study.

OBJECTIVE: to evaluate the association between XPD and XRCC3 polymorphisms and oral squamous cell carcinoma (OSCC). DESIGN: the sample consisted of 54 cases of OSCC and 40 cases of inflammatory fibrous hyperplasia (IFH). Genotypes were determined by the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. RESULTS: XPD-Lys/Gln was more common in IFH (n=28; 70%) than in OSCC (n=24; 44.4%) (OR: 0.3; p<0.05). XPD-Gln was more frequent in high-grade lesions (0.48) than in low-grade lesions (0.21) (OR: 3.4; p<0.05). The Gln/Gln genotype was associated with III and IV clinical stages (OR: 0.07; p<0.05). XRCC3-Met was more frequent in OSCC (0.49) than in IFH (0.35) (OR: 2.6; p<0.05). The Met/Met genotype was associated with the presence of metastases (OR: 8.1; p<0.05) and with III and IV clinical stages (OR: 0.07; p<0.05). CONCLUSIONS: in this sample, the frequency of XPD-Gln in IFH suggests that this variant may protect against OSCC. The presence of the XRCC3-Met allele seems to contribute to the development of OSCC, metastases and more advanced stages in these lesions.