Polymorphisms in drug-metabolizing genes and urinary bladder cancer susceptibility and prognosis: Possible impacts and future management

Epidemiological studies have shown the association of genetic variants with risks of occupational and environmentally induced cancers, including bladder (BC). The current review summarizes the effects of variants in genes encoding phase I and II enzymes in well-designed studies to highlight their contribution to BC susceptibility and prognosis. Polymorphisms in genes codifying drug-metabolizing proteins are of particular interest because of their involvement in the metabolism of exogenous genotoxic compounds, such as tobacco and agrochemicals. The prognosis between muscle-invasive and non-muscle-invasive diseases is very different, and it is difficult to predict which will progress worse. Web of Science, PubMed, and Medline were searched to identify studies published between January 1, 2010, and February 2023. We included 73 eligible studies, more than 300 polymorphisms, and 46 genes/loci. The most studied candidate genes/loci of phase I metabolism were CYP1B1, CYP1A1, CYP1A2, CYP3A4, CYP2D6, CYP2A6, CYP3E1, and ALDH2, and those in phase II were GSTM1, GSTT1, NAT2, GSTP1, GSTA1, GSTO1, and UGT1A1. We used the 46 genes to construct a network of proteins and to evaluate their biological functions based on the Reactome and KEGG databases. Lastly, we assessed their expression in different tissues, including normal bladder and BC samples. The drug-metabolizing pathway plays a relevant role in BC, and our review discusses a list of genes that could provide clues for further exploration of susceptibility and prognostic biomarkers.

Metalloproteinase 9 immunostaining profile is positively correlated with tumor grade, extraprostatic extension and biochemical recurrence in prostate cancer

Metastasis is the main problem in the treatment of prostate cancer (PCa), and for it to occur, proteolytic enzymes must remodel the extracellular matrix (ECM) surrounding the tumor. The most important group of enzymes with this action include the matrix metalloproteinases (MMPs), which act on various substrates cleaving ECM components. The present study aimed to evaluate the protein immunostaining profiles of matrix metalloproteinase 2 (MMP-2) and 9 (MMP-9) in PCa Brazilian patients using the indirect immunohistochemical methodology. The tissue samples (n = 178), 60 from malignant tumor, 58 from adjacent non-tumor, and 60 from ECM, were evaluated according to the immunostaining intensity. The malignant tumor cytoplasmic MMP-2 immunostaining was more intense than in ECM (p = 0.001), but it did not correlate with any clinical-pathological parameter. The MMP-9 staining was similar in tumor cytoplasm, adjacent non-tumor cytoplasm and ECM, but showed significant positive correlations with ISUP grade (p = 0.044; Tau=0.249), extraprostatic extension (p = 0.025; Tau=0.309), and biochemical recurrence (p = 0.048; Tau=0.306). A significant positive correlation was also observed between MMP-2 and MMP-9 in all cell compartments analyzed. Although further research is warranted to elucidate the precise mechanisms underlying these observations, our findings suggest MMP-9 as a promising candidate marker for tissue invasion that could be used in predicting the progression and prognosis of PCa.

Allelic variants and immunostaining profile in CXCL12/CXCR4 axis: An investigation of association with prognosis in prostate cancer

Prostate cancer (PCa) is the malignant neoplasm that most commonly affects men and is an important cause of death. It can be detected by changes in serum levels of Prostate Specific Antigen (PSA) and digital rectal examination, but often symptoms do not appear until advanced stages and metastases. The C-X-C Motif Chemokine Ligand 12/C-X-C Motif Chemokine Receptor 4 (CXCL12/CXCR4) axis acts in cell migration and may be involved in the metastatic process. In this context, the aim of this study was to evaluate the allelic variants rs1801157 (CXCL12) and rs2228014 (CXCR4) and the immunostaining of CXCR4 protein as candidates for prognostic markers in PCa. Samples (n = 60) were divided according to prognostic parameters (with and without metastasis at diagnosis) in tree groups: better prognosis, worse prognosis with metastasis at diagnosis and worse prognosis without metastasis at diagnosis, and immunostaining was evaluated by indirect immunohistochemistry, considering tumoral and adjacent tissues from the same patient (n = 120). A significant association was found between the C allele of rs2228014 (CXCR4) and the extraprostatic extension. For CXCR4 immunostaining a weak labeling and a cytoplasmic localization predominated, as well as a significant difference between malignant versus adjacent tissue, with higher protein expression in the malignant tissue. A significant association was found between CXCR4 tumor immunostaining with TNM staging (T2b-T2c) and PSA level (> 20 ng/mL). None of the allelic variants affected CXCR4 immunostaining. Prognostic groups did not differ in allelic variant frequency or immunostaining profile. Findings suggest that CXCR4 receptor may be one of the ways to worsen the prognosis of prostatic cancer.

APOBEC3A/B Polymorphism Is Not Associated with Human Papillomavirus Infection and Cervical Carcinogenesis

The persistence of a high-risk Human papillomavirus (HPV-HR) infection of the cervix results in different manifestations of lesions depending on the immunologic capacity of the host. Variations in apolipoprotein B mRNA editing enzyme catalytic polypeptide (APOBEC)-like genes, such as the APOBEC3A/B deletion hybrid polymorphism (A3A/B), may contribute to cervical malignancy in the presence of HPV. The aim of this study was to investigate the association between the A3A/B polymorphism and HPV infection and the development of cervical intraepithelial lesions and cervical cancer in Brazilian women. The study enrolled 369 women, who were categorized according to the presence of infection and subdivided according to the degree of intraepithelial lesion and cervical cancer. APOBEC3A/B was genotyped by allele-specific polymerase chain reaction (PCR). As for the A3A/B polymorphism, the distribution of genotypes was similar between groups and among the analyzed subgroups. There were no significant differences in the presence of infection or development of lesions, even after exclusion of confounding factors. This is the first study to show that the A3A/B polymorphism is not associated with HPV infection and the development of intraepithelial lesions and cervical cancer in Brazilian women.

Flavonoid brachydin B decreases viability, proliferation, and migration in human metastatic prostate (DU145) cells grown in 2D and 3D culture models

Brachydin B (BrB) is a unique dimeric flavonoid extracted from Fridericia platyphylla (Cham.) LG Lohmann with different biological activities. However, the antitumoral potential of this flavonoid is unclear. In our study, we evaluated the effects of the BrB flavonoid on cell viability (MTT, resazurin, and lactate dehydrogenase assays), proliferation (protein dosage and clonogenic assay), and migration/invasion (3D ECM gel, wound-healing, and transwell assays) of metastatic prostate (DU145) cells cultured both as traditional 2D monolayers and 3D tumor spheroids in vitro. The results showed that the BrB flavonoid promotes cytotoxic effects from ≥1.50 μM after 24 h of treatment in DU145 cells in monolayers. In 3D prostate tumor spheroids, BrB also induced cytotoxic effects at higher concentrations after longer treatment (48, 72, and 168 h). Furthermore, BrB treatment is associated with reduced DU145 clonogenicity in 2D cultures, as well as decreased area/volume of 3D tumor spheroids. Finally, BrB (6 μM) reduced cell migration/invasion in 2D monolayers and promoted antimigratory effects in DU145 tumor spheroids (≥30 μM). In conclusion, the antitumoral and antimigratory effects observed in DU145 cells cultured in 2D and 3D models are promising results for future studies with BrB using in vivo models and confirm this molecule as a candidate for metastatic prostate cancer therapy.

Tissue immunostaining of candidate prognostic proteins in metastatic and non-metastatic prostate cancer

PURPOSE

Prostate cancer (PCa) lacks specific markers capable of distinguishing aggressive tumors from those with indolent behavior. Therefore, the aim of this study was to evaluate the immunostaining of candidate proteins (PTEN, AKT, TRPM8, and NKX3.1) through the immunohistochemistry technique (IHC) on patients with metastatic and non-metastatic PCa.

METHODS

Tissues from 60 patients were divided into three groups categorized according to prognostic parameters: better prognosis (n = 20), worse prognosis (n = 23), and metastatic (n = 17). Immunostaining was analyzed by a pathologist and staining classifications were considered according to signal intensity: (0) no staining, (+) weak, and (++ and +++) intermediate to strong.

RESULTS

AKT protein was associated (p = 0.012) and correlated (p = 0.014; Tau = - 0.288) with the prognostic groups. The immunostaining for TRPM8 (p = 0.010) and NKX3.1 (p = 0.003) proteins differed between malignant tumor and non-tumoral adjacent tissue as well as for proteins in cellular locations (nucleus and cytoplasm). TRPM8 was independently associated with the ISUP grade ≥ 4 (p = 0.024; OR = 8.373; 95% CI = 1.319-53.164). The NKX3.1 showed positive and predominantly strong immunostaining in all patients in both tumoral and non-tumoral adjacent tissues. All metastatic samples had positive immunostaining, with strong intensity for NKX3.1 (p = 0.021; Tau = - 0.302). In the non-metastatic group, this strong protein staining was not observed in any patients.

CONCLUSION

This study confirmed that NKX3.1 is highly specific for prostate tissue and indicated that NKX3.1, AKT, and TRPM8 may be candidate markers for prostate cancer prognosis.

An MGMT Allelic Variant Can Affect Biochemical Relapse in Prostate Cancer Patients

BACKGROUND/AIM

Prostate cancer (PCa) is one of the most frequent neoplasms in men around the world. In recent years, the search for new biomarkers with greater prognostic potential for PCa has intensified. This study aimed to evaluate single nucleotide polymorphisms (SNPs) and a combined panel of these polymorphisms in relation to biochemical recurrence in patients who were through prostatectomy, with an average of 7 years of follow-up.

MATERIALS AND METHODS

Patients diagnosed with PCa (n=197) participated in this cohort study. Thirteen SNPs were analyzed: rs2279115 (BCL-2), rs26677604 (CASP3), rs1052571 (CASP9), rs11781886 (NKX3-1), rs2735343 (PTEN), rs2494750 (AKT1), rs2699887 (PI3KCA), rs3195676 (AMACR), rs17302090 (AR), rs2536 (mTOR), rs1695 (GSTP1), rs2308321 (MGMT) and rs1544410 (VDR). Variants were combined and four main panels were defined: cell death, cell survival, growth receptors, and metabolism. Genotyping was performed by real-time PCR.

RESULTS

We did not observe any significant relation between the panels of variants analyzed, apart from the rare allele (G) of rs2308321 (MGMT) that was associated with a higher risk of recurrence (p=0.036) when compared to the prevalent (A) in the allelic model.

CONCLUSION

This MGMT variant occurs in an exon, and it could potentially affect DNA repair and, therefore, the biochemical relapse of PCa patients.

COVID-19: The question of genetic diversity and therapeutic intervention approaches

Coronavirus disease 2019 (COVID-19), caused by the Severe Acute Respiratory Syndrome Coronavirus type 2 (SARS-CoV-2), is the largest pandemic in modern history with very high infection rates and considerable mortality. The disease, which emerged in China's Wuhan province, had its first reported case on December 29, 2019, and spread rapidly worldwide. On March 11, 2020, the World Health Organization (WHO) declared the COVID-19 outbreak a pandemic and global health emergency. Since the outbreak, efforts to develop COVID-19 vaccines, engineer new drugs, and evaluate existing ones for drug repurposing have been intensively undertaken to find ways to control this pandemic. COVID-19 therapeutic strategies aim to impair molecular pathways involved in the virus entrance and replication or interfere in the patients' overreaction and immunopathology. Moreover, nanotechnology could be an approach to boost the activity of new drugs. Several COVID-19 vaccine candidates have received emergency-use or full authorization in one or more countries, and others are being developed and tested. This review assesses the different strategies currently proposed to control COVID-19 and the issues or limitations imposed on some approaches by the human and viral genetic variability.

Development of cervical intraepithelial lesions and cervical cancer is not influenced by SOD2 RS4880 polymorhism

Some of the more than 200 known HPV types are essential for cervical cancer development, the third type of cancer most incident in the female population. However, for the malignant transformation occur, some cofactors are needed, as the reactive oxygen species (ROS), which can be neutralized by the antioxidant system. The SOD2 enzyme, encoded by the same name gene, is found in mitochondria and is part of the first line of defense against oxidative stress damage. Genetic polymorphisms can act by altering the efficiency of the enzyme, among which the most studied is the rs4880. Thus, the purpose of the present study was to evaluate the association of this polymorphism with HPV infection and the development of low and high grade squamous intraepithelial lesions (LSIL and HSIL) and cervical cancer, in 407 women attended by the public health system in Brazil. HPV detection in cervical secretion samples was carried out by polymerase chain reaction (PCR) and blood samples were used for polymorphism genotyping through PCR followed by restriction fragment length polymorphism (RFLP). PCR and restriction products were subjected to 10% polyacrylamide gel electrophoresis. HPV negative group (control) included 158 women and the HPV positive group (case) 249 women. The infected group was divided into No Lesion (n = 90), LSIL (n = 20), HSIL (n = 67) and cervical cancer (n = 72). The data found on socio-epidemiological characteristics and habits corroborated with data found in the literature. The distribution of genotypes in the control group was 51.9% women TC, 29.8% TT and 18.3% CC. In the case group, the distribution was 55.0% women TC, 26.1% TT and 18.9% CC. This is the first study evaluating the influence of SOD2 rs4880 polymorphism on HPV infection, the development of cervical intraepithelial lesions and cervical cancer in a Brazilian population, although additional studies are needed to corroborate the results.

TGFβ1 pathway components in breast cancer tissue from aggressive subtypes correlate with better prognostic parameters in ER-positive and p53-negative cancers

Background

TGFβ signaling exerts context-specific effects in breast cancer (BC) pathogenesis and single nucleotide polymorphisms (SNPs) in TGFβ-signaling components play a role in the genetic control of their expression and in BC susceptibility and clinical presentation. However, studies investigating the association between the TGFβ-signaling molecules and BC prognosis rarely considered disease subtypes and SNPs. Therefore, the present study aimed to evaluate the expression of TGFβ-signaling components in BC tissue from patients with available data regarding TGFB1 and TGFBR2 SNPs and plasmatic TGFβ1 levels.

Methods

Immunostaining for TGFβ1, TGFβRII and phosphorylated (p)-SMAD2/3 was investigated in primary tumor tissue from 34 patients with luminal-B-HER2+ (LB-HER2), HER2-enriched (HER2) and triple negative (TN) BC subtypes genotyped for TGFB1 (rs1800468, rs1800469, rs1800470 and rs1800471) and TGFBR2 (rs3087465) SNPs.

Results

Strong positive correlations were observed between TGFβ1, TGFβRII and p-SMAD2/3 in tumor tissue, and an inverse correlation was observed between intratumor and plasmatic TGFβ1 levels in TN BCs. In LB-HER2+ tumors, p-SMAD2/3 was associated with older age at diagnosis and inversely correlated with p53 staining and lymph-node metastasis, while tumor-size negatively correlated with TGFβ1 and TGFβRII in this BC subgroup. Also, in p53-negative BCs, tumor size and Ki67 negatively correlated with both TGFβ1, TGFβRII and p-SMAD2/3. No correlation was found between SNPs and TGFβ1-signaling components expression.

Conclusion

TGFβ1 canonical signaling is activated in approximately half of BCs, and correlation between TGFβ components indicate a paracrine activation, which may exert tumor suppressor effects in p53-negative or Luminal-B-HER2+ subgroups.

Effects of GSTT1 and GSTM1 polymorphisms in glutathione levels and breast cancer development in Brazilian patients

Polymorphisms in the glutathione transferase enzymes (GSTs) genes have been associated with susceptibility to develop breast cancer (BC), but few are known regarding its role on this disease prognosis and impact on antioxidant status. This study evaluated the polymorphisms of GSTM1 and GSTT1 genes and their relationship with BC susceptibility and prognostic, as well as its impact on plasma reduced glutathione (GSH) levels. The present study included 121 women with invasive ductal BC and 151 healthy controls. Polymorphisms analyses were performed using the polymerase chain reaction (PCR) technique and GSH levels were measured with the Ellman's reagent. GSTT1 (OR 1.29; p = 0.39) and GSTM1 (OR 1.03; p = 0.91) polymorphisms did not show any association with BC susceptibility. The mean concentration values in nmol/L of GSH were 20.37 ± 5.82 for patients with null genotypes for both genes, 19.75 ± 3.47 for null GSTT1, 17.22 ± 1.35 for active GSTT1, 18.82 ± 1.96 for absent GSTM1, and 16.59 ± 1.66 for active GSTM1, but no significance was found. Therefore, it can be concluded that the behavior of these polymorphisms concerning BC might be not only related to the absence of enzymatic expression but may also be related to the body's response with its antioxidant mechanisms and it should be further studied.

Transforming growth factor beta 1 (TGFβ1) plasmatic levels in breast cancer and neoplasia-free women: Association with patients' characteristics and TGFB1 haplotypes

Transforming growth factor beta 1 (TGFβ1) is a pleiotropic cytokine that acts in a context-dependent manner. In breast cancer (BC) this cytokine exerts subtype- and stage-specific roles, inhibiting poorly aggressive tumors while enhances the invasive potential of highly aggressive cancers. Single-nucleotide polymorphisms (SNPs) affecting TGFβ1 production largely reflect this pattern of association, but studies investigating systemic TGFβ1 levels in BC patients and their association with clinical features or SNPs produced conflicting conclusions. Therefore, the present work investigated plasmatic TGFβ1 levels through enzyme linked immunosorbent assay (ELISA) in 341 individuals previously genotyped for four TGFB1 SNPs [G-800A (rs1800468), C-509T (rs1800469), T29C (rs1800470) and G74C (rs1800471)], encompassing 184 neoplasia-free women with clinical information regarding health status, 113 treatment-free pre-surgery BC patients and 44 treated BC patients. Results have shown that TGFβ1 levels varied greatly in function of health status in neoplasia-free women, and disease-free individuals had higher TGFβ1 levels than both treatment-free or treated BC patients. There was no correlation between TGFβ1 with clinicopathological features in treatment-free BC general group, but it was negatively correlated with tumor size in luminal-B-HER2+ patients and with histopathological grade in triple-negative group. Also, TGFB1 ACTG haplotype (from G-800A to G74C) was associated with decreased TGFβ1 levels compared to the reference GCTG haplotype, and regression analyses showed that this association was independent of age, health status or BC diagnosis. In conclusion, several factors may influence TGFβ1 levels, and ACTG haplotype seems to be an important factor regulating TGFβ1 production.

CCR5 and CXCL12 allelic variants: Possible association with childhood neuroblastoma susceptibility?

Neuroblastoma (NB) is a heterogeneous and particularly malignant childhood neoplasm in its higher stages, prone to form metastasis in selected organs and for which there is still no efficient treatment available beyond surgery. Evidence indicates that chemokines and their receptors present involvement as mediators of neuroinflammation and have a neurophysiological role. In the present study, we aimed to verify if CCR5 (rs333) and CXCL12 (rs1801157) allelic variants were associated with NB. For CCR5 (rs333) D32 carriers (OR: 5.96, IC: 2.21-16.06) and for CXCL12 genotype 3'A/3'A (OR:26.18, IC:6.15-111.4) there were statistically significant differences as well to allelic frequency (OR:4.20, IC: 2.19-8.03). Although no correlation was verified regarding prognostic parameters for both CCR5 and CXCL12 polymorphic variants, these polymorphisms may be associated with NB susceptibility which deserve attention for future investigations.

CCL5 protein level: influence on breast cancer staging and lymph nodes commitment

Many tumor cells express chemokines and chemokine receptors, and these molecules can contribute to distinct modes of metastasis processes. It is known that they play a crucial role in breast cancer (BC) tumorigenesis and progression. Considering this, it was investigated a possible role for C-Chemokine receptor type 5(CCR5) polymorphism (rs333/delta32) by conventional polymerase chain reaction (PCR) and CCL5 (C-C motif chemokine ligand 5) protein level by immunosorbent assay (ELISA) in 47 BC patients (resulting in 47 tumoral tissue samples and 47 adjacent normal tissue samples). There was a significant difference between CCL5 level in tumoral and adjacent normal tissues for the same BC patients (p < 0.0001). A significant association was also found for CCL5 level in relation to lymph nodes commitment (p = 0.03). Likewise, there was a significant difference in CCL5 level from tumor tissue of stage III in relation to stage I (p < 0.02). On the other hand, it was verified that CCR5-delta32 polymorphism presented no significant association in relation to CCL5 protein level. Considering the present findings, we suggest that CCL5 may be involved in BC staging and metastasis process.

HER2 Ile655Val polymorphism is negatively associated with breast cancer susceptibility

BACKGROUND

The HER2 (human epidermal growth factor receptor-2) Ile655Val (rs1136201) genetic polymorphism can alter the receptor structure and its auto-activation, which can modify the signal transduction and, consequently, the cell cycle regulation. For this reason, this polymorphism has been extensively investigated as a candidate marker for breast cancer (BC). In this context, the aim of this study was to evaluate the possible influence of HER2 Ile655Val in BC susceptibility and prognostic factors in a Brazilian population.

METHODS

Polymorphism genotype was assessed through RFLP-PCR in 107 BC patients with clinicopathological data available and in 150 women with no evidence of neoplasia and with no familial history of BC as control group. Association between this polymorphism and BC susceptibility and clinical parameters was evaluated through odds ratio (OR) and chi-squared or Fisher's exact test, respectively.

RESULTS

A significant negative association between valine allele and BC susceptibility in dominant model was found (OR 0.5; 95% CI 0.27-0.93, P = .036). No significant association was found in relation to BC clinicopathological features (tumor size, lymph nodes commitment, histological grade, HER2 overexpression, hormonal receptors, p53, and Ki-67).

CONCLUSION

Although this polymorphism did not demonstrate potential as a prognostic marker, it may be a suitable susceptibility marker for BC.

Transforming growth factor beta 1 (TGFβ1) polymorphisms and haplotype structures have dual roles in breast cancer pathogenesis

PURPOSE

Despite the documented dual role of TGFβ1 in breast cancer (BC) pathogenesis, the subtype-specific influences of its polymorphisms remain undocumented. The present study investigated the effects of the TGFB1 promoter region (rs1800468 or G-800A and rs1800469 or C-509T) and signal peptide (rs1800470 or C29T and rs1800471 or G74C) single nucleotide polymorphisms (SNPs) and their haplotype structures on the susceptibility and clinicopathological presentation of BC subtypes.

METHODS

TGFB1 genotypes were assessed by PCR-RFLP and haplotype structures were inferred for 323 BC patients and 405 neoplasia-free women, and case-control analyses were performed by logistic regression adjusted by age. Clinicopathological parameters (age at diagnosis, tumor size, histopathological grade, lymph node metastasis, proliferation index and disease stage) were tested for correlation with TGFB1 variants. All statistical analyses were two-tailed with an alpha level of 0.05.

RESULTS

Variants related to increased TGFβ1 production (C-509T SNP and GTCG haplotype) were associated with increased susceptibility to HER2⁺ tumors and correlated with worse prognostic parameters in HER2⁺ and triple-negative (TN) BCs, but correlated negatively to Ki67 in ER/PR⁺HER2^- tumors. Conversely, low TGFβ1 production variants (C29T SNP and GCTG haplotype) were protective against HER2⁺ tumors and correlated negatively with prognostic parameters in HER2⁺ and TN BCs, while indicating higher proliferation rates in ER/PR⁺HER2^- tumors. Furthermore, the GCCG haplotype was associated with decreased susceptibility to ER/PR⁺HER2^- tumors, but correlated positively with Ki67 in this subgroup.

CONCLUSION

The present study indicates that TGFB1 variants have subtype-specific roles in BC and may switch from tumor suppressor to promoter during tumor development, consistent with TGFβ1 dual role in BC pathogenesis.

Glutathione S-transferases deletions may act as prognosis and therapeutic markers in breast cancer

Breast cancer (BC) is the main worldwide neoplasia in women. The metabolic balance between xenobiotic absorption and elimination rates plays an important role in preventing DNA damage and, consequently, tumor development. The glutathione S-transferases (GSTs), such as GSTM1 and GSTT1, and the NAD(P)H quinone oxidoreductase are important enzymes involved in phase II detoxification reactions. Deletions in GSTM1 and GSTT1, and single-nucleotide polymorphism (SNP) in NQO1 (rs1800655) have been investigated in cancer context, revealing conflicting results. The present study analyzed these genetic polymorphisms in 121 BC patients and 151 BC-free controls in order to verify if they could act as susceptibility modifiers and/or prognostic factors. Binary logistic regressions adjusted by age were performed to assess associations between allelic variants and interactions in polymorphisms combination with BC susceptibility, but no significant association was found. Genotypes distribution was also compared between BC subtypes, but no significant difference was observed (p > 0.05). GSTM1 deletion was significantly associated with histopathological grade, with a greater proportion of patients presenting grade III tumors (p = 0.007). Univariate analysis identified tumor size as the only clinicopathological parameter potentially associated with recurrence risk in patients that received adjuvant chemotherapy (p < 0.1). Thus, logistic regression analysis adjusted by tumor size revealed a positive association between GSTT1 deletion and recurrence risk in general BC (OR 4.25; p = 0.04), while GSTM1 was negatively associated with recurrence risk in ER/PR⁺HER2^- samples (OR 0.07; p = 0.03). In conclusion, the present study indicated that GSTT1 deletion was associated with increased recurrence risk, while GSTM1 correlated with worst prognosis parameters at diagnosis, but was negatively associated with recurrence risk in luminal subtype samples.

Genetic Polymorphism in the Promoter Region of Serotonin Transporter: Implications for Ethanol Abuse in Children and Adolescents

OBJECTIVES

To provide a review of published literature regarding genetic polymorphism of serotonin transporter gene, named as 5-HTTLPR, and its potential role as a susceptibility marker for ethanol abuse in childhood and adolescence.

METHODS

A literature review of several databases was conducted with the following keywords: 5-HTTLPR, children or adolescents or teenagers, susceptibility, alcohol or ethanol, abuse or misuse.

RESULTS

Alcohol interacts with serotonergic synaptic transmission in several ways, and the reduced availability of serotonin transporters might foster brain dysfunction, driving to alcohol abuse. The initial use of ethanol in children and adolescents is determined primarily by environmental influences, whereas the establishment of drinking patterns is strongly controlled by genetic factors. Functional polymorphic variants in the promoter region of the 5-HTTLPR gene have age-dependent effects in alcohol abuse. This polymorphism, mapped to the 5' region of the SLC6A4, is a variable number of tandem repeats (VNTR) and involves a direct repeat of 20-23 base pairs GC-rich sequences, comprising a short (S) allele, consisting of 14 repeats, and a long (L) allele, with 16 repeats. Additional variants have been described, although their influences on childhood and adolescence ethanol use are not clear.

CONCLUSION

The influence of the 5-HTTLPR allelic variants in children and adolescent misuse of alcohol might be considered for clinical management, preventing long-term behavior problem. Identifying genetic markers associated to the potential alcohol misuse or abuse could be useful in guiding management and formulating effective coping strategies.

Genetic polymorphisms by deletion in genes that encode for glutathione S-transferases are associated with nicotine dependence and tobacco use-related medical disorders

OBJECTIVE

We examine the relationship between nicotine dependence (ND) and ND-related medical disease and polymorphisms by deletion in genes that encode glutathione S-transferases (GSTs), e.g. GSTM1 and GSTT1. Individuals with homozygous gene deletions show deficiencies in GSTs enzyme activities impairing detoxification.

METHODS

This study comprised 182 tobacco users and 182 controls (neversmokers). GSTM1 and GSTT1 polymorphisms were assessed using a Multiplex- PCR based protocol.

RESULTS

Logistic regression analyses showed a significant association between ND and the GSTM1 and GSTT1 null genotypes. There were no significant associations between GSTT1, GSTM1 and GSTT1/M1 genetic variants and the Fagerström test for ND, age at onset, smoking cessation or a family history of ND. Patients with ND had increased rates of a family ND history and an increased prevalence of cardiovascular disease, hypertension, and lung disease. The null genotypes were associated with hypertension (i.e. GSTT1 × ND interaction), diabetes type 2 (i.e. GSTM1 × GSTT1 interaction), lung disease (i.e. GSTM1 × ND interaction) and cancer (i.e. GSTT1). The results show that GST null genotypes may confer protection against ND while they increase risk towards ND-related medical disorders.

STin2 VNTR polymorphism is associated with comorbid tobacco use and mood disorders

BACKGROUND

There is a significant comorbidity between mood disorders and tobacco use disorder (TUD), which may be related to both genetic and environmental factors. Gene variants of the 5-HT transporter, such as STin2 VNTR (a variable number of tandem repeats in the functional serotonin transporter intron 2) may be associated with mood disorders and TUD.

AIMS

This study aimed to delineate the association between the STin2 genetic polymorphism and comorbid TUD and mood disorders, including depression or bipolar disorder.

METHODS

We examined the STin2 VNTR polymorphism in never-smokers (n=113); patients with mood disorders without TUD (n=62); patients with TUD without mood disorders (n=90); and patients with both disorders (n=95).

RESULTS

We found a significant association between the STin2 genetic polymorphism and the above diagnostic groups whereby the STin2.12 allele shows a positive association with comorbid TUD and mood disorders (Odds ratio=3.07, 95% CI=1.41-6.68), while the STin2.10/10 homozygous genotype shows a negative association (Odds ratio=0.34, 95% CI=0.16-0.74). Adjusting for years of education, age, gender, marital status and ethnicity did not change these results, but showed that TUD was associated with lower education levels and less stable relationships, whereas mood disorders were related to female gender. A family history of TUD was significantly associated with TUD in subjects without mood disorders only.

CONCLUSIONS

The STin2.12 allele is positively and the STin2.10/10 genotype is negatively associated with comorbid TUD and mood disorders, depression or bipolar depression, suggesting that biological endophenotypes, e.g. disorders in serotonin metabolism, may in part underpin this comorbidity.

SLC6A4 STin2 VNTR genetic polymorphism is associated with tobacco use disorder, but not with successful smoking cessation or smoking characteristics: a case control study

Background

The aim of this study was to determine if variable number of tandem repeats (VNTR) in the second intron (STin2) of the serotonin transporter (SLC6A4) gene was associated with tobacco use disorder, successful smoking cessation, or smoking characteristics. In this case–control study, patients with current tobacco use disorder, diagnosed according to DSM IV criteria (n = 185), and never-smokers, diagnosed according to CDC criteria (n = 175), were recruited and received 52 weeks of combined pharmacotherapy and cognitive therapy. Successful smoking cessation was defined as exhaled carbon monoxide < 6 ppm. SLC6A4 gene STin2 VNTR polymorphism was assessed using a Multiplex-PCR-based method. At baseline, participants were evaluated using the Fagerström Test for Nicotine Dependence (FTND) and the ASSIST scale.

Results

The STin2.12 allele (OR = 2.45; 95% CI = 1.44-4.15, p < 0.001) was associated with an increased risk for tobacco use disorder, while the STin2.10/10 genotype (OR = 0.42; 95% CI 0.25-0.71, p < 0.001) decreased risk. There were no significant associations between tobacco use disorder and the STin2.10 or STin2.9 alleles or the other genotypes (STin2.12/12, 12/10, 12/9, 10/9 or 9/9). There were no significant associations between the STin2 genotypes and alleles and successful smoking cessation, smoking characteristics and increased alcohol or sedative use risk.

Conclusions

Our results suggest that the STin2.10/10 genotype and STin2.12 allele are associated with tobacco use disorder or nicotine dependence, but not with treatment response or severity of dependence. It is hypothesized that the ST2in.12 allele by modulating the metabolism of serotonin may participate in the pathophysiology of tobacco use disorder or nicotine dependence.

Molecular markers for breast cancer: prediction on tumor behavior

Breast cancer is one of the most common cancers with greater than 1,300,000 cases and 450,000 deaths each year worldwide. The development of breast cancer involves a progression through intermediate stages until the invasive carcinoma and finally into metastatic disease. Given the variability in clinical progression, the identification of markers that could predict the tumor behavior is particularly important in breast cancer. The determination of tumor markers is a useful tool for clinical management in cancer patients, assisting in diagnostic, staging, evaluation of therapeutic response, detection of recurrence and metastasis, and development of new treatment modalities. In this context, this review aims to discuss the main tumor markers in breast carcinogenesis. The most well-established breast molecular markers with prognostic and/or therapeutic value like hormone receptors, HER-2 oncogene, Ki-67, and p53 proteins, and the genes for hereditary breast cancer will be presented. Furthermore, this review shows the new molecular targets in breast cancer: CXCR4, caveolin, miRNA, and FOXP3, as promising candidates for future development of effective and targeted therapies, also with lower toxicity.

TGF-β polymorphism and its expression correlated with CXCR4 expression in human breast cancer

The role of chemokines and the growth factors has been extensively analyzed both in cancer risk and tumor progression. The transforming growth factor beta (TGF-β) and chemokine (C-X-C motif) receptor 4 (CXCR4) genes are implicated in several diseases, including breast cancer. Genomic DNA was obtained from 21 samples of peripheral blood or from normal tissue, previously fixed in formalin and embedded in paraffin for TGF-β T869C polymorphism analyses. Total cellular RNA was extracted from the same 21 patients, but from fresh tissue (tumor and adjacent healthy from the same breast) for expression analysis by Real Time PCR. No significant differences were observed in genotype distribution according to clinicopathological characteristics. Transforming growth factor beta (TGF-β) mRNA expression was assessed according to T869C polymorphism and CC patients presented a higher TGF-β expression but not significant when compared to other genotypes (p = 0.064). A positive correlation was observed in relative mRNA expressions of CXCR4 and TGF-β (p = 0.020). It is known that overexpression of TGF-β by both tumor and stromal tissue can facilitate the development of metastases, mainly by TGF-β stimulated angiogenesis and increased tumor cell motility. Our findings suggested a role of these genes as progression markers for breast carcinoma.

Association between the STin2 VNTR polymorphism and smoking behavior in oral cancer patients and healthy individuals

The serotonergic system may be involved in smoking behavior since the intake of nicotine increases serotonin secretion in the CNS. Moreover, evidence supporting the beneficial effect of selective serotonin reuptake for quitting smoking suggesting that the serotonin transporter (5-HTT) is a plausible target for the understanding and elucidation of smoking behavior. The transcriptional activity of its human gene (SLC6A4) is modulated by a polymorphism described in the second intron, the STin2 VNTR, which thus may interfere with 5-HTT synthesis. In this study was analyzed the polymorphism STin2 VNTR of 60 smokers male patients diagnosed for oral carcinoma, 61 male smokers without cancer and 65 non-smoker healthy blood donors. The STin2. 9 allele carriers were more present in smoker groups (with cancer and without cancer, respectively) than in the non-smoker (OR = 7.11, 95% CI = 0.83-60.91 and OR = 24.73; IC 95% = 3.17-192.66). Conversely, individuals carrying allele 10 were more prevalent in non-smokers compared with smokers (oral cancer patients and individuals without cancer, respectively), showing a protective factor of this allele (OR = 0.56; 95% CI = 0.24-1.33 and OR = 0.46; 95% CI = 0.20-1.07). This is the first report of a study assessing the importance of STin2 VNTR smoking behavior in Brazilian individuals and the association of STin2. 9 allele carriers in nicotine dependence. It is suggested that individuals with low serotonin concentration in the central nervous system, probably due to the presence of the allele for high expression of 5-HTT,especially STin2. 9, were more susceptible to nicotine dependence. Moreover, individuals with the 10 allele might have less risk for nicotine dependence.