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.

Wilms' tumor susceptibility: possible involvement of FOXP3 and CXCL12 genes

Background

Wilms’ tumor is an embryonal neoplasm of the kidney that accounts for approximately 6 % of all childhood tumors. The chemokine CXCL12 (C-X-C chemokine ligand 12) and its ligand CXCR4 (C-X-C chemokine receptor type 4) are involved in the development of several organs, including the kidney, and are also associated with tumor growth and metastasis. FOXP3 (forkhead transcription factor 3) was initially described as a marker for regulatory T cells; however, its expression in several types of tumor cells has already been described and may have prognostic significance. The aim of the present study was to analyze rs3761548 and rs2232365 FOXP3 polymorphisms, as well as evaluate rs1801157 CXCL12 polymorphism in Wilms’ tumor samples.

Methods

Polymorphisms were evaluated in 32 patients and 78 neoplasia-free controls. Genotypes of rs1801157 were determined using PCR-restriction fragment length polymorphism (PCR-RFLP) method, and genotypes of rs2232365 and rs3761548 were determined using allele-specific PCR (AS-PCR).

Results

The case-control study indicated a significant association for allele A carriers of rs1801157 polymorphism in relation to Wilms’ tumor susceptibility (OR = 5.261; 95 % CI 2.156 to 12.84; p = 0.0002). The opposite was observed in male carriers of G allele for rs2232365 polymorphism (OR 0.1164; 95 % CI 0.0227 to 0.5954; p = 0.0091) or when male and female subjects were analyzed (OR = 0.1304; 95 % CI 0.05013 to 0.3394; p < 0.0001).

Conclusions

All in all, these markers may contribute to this neoplasia susceptibility and progression; however, further studies are needed to real clarify their role in Wilms’ tumor pathogenesis.

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.

Oral carcinoma epidemiology in Paraná State, Southern Brazil

Oral carcinoma is the sixth most frequent type of cancer in the world and the seventh most common in Brazil (the country with the highest incidence in Latin America). Mean five-year survival remains one of the lowest among the main cancers, thus justifying studies that contribute to the development of preventive strategies. The aim of this study was to compare the epidemiological, clinical, and histological characteristics of 91 patients with oral carcinoma. Mean age was 58.62 +/- 10.46 years, and male-to-female ratio was 6.6:1.0 (79 men and 12 women). European descendants predominated with 79 patients (86.8%). Eighty-five individuals (93.4%) smoked and 70 (76.9%) consumed alcohol regularly. Anatomical distribution of tumors was: 27 (29.7%) tongue; 18 (19.8%) floor of mouth; 11 (12.1%) oropharynx; and 11 (12.1%) oral mucosa. Fifty-seven patients (62.6%) presented lymph node involvement and three (3.3%) had distant metastases. Surgery and radiotherapy were used in 43.2% of patients. With the exception of the male/female ratio (which was higher), our data are consistent with previous studies on oral carcinoma patients.

Lack of association among polymorphic xenobiotic-metabolizing enzyme genotypes and the occurrence and progression of oral carcinoma in a Brazilian population

BACKGROUND

A case control association study was carried out to investigate polymorphisms in genes CYP1A1 (3801T > C), GSTM1, and GSTT1 (null genotypes) and oral squamous cell carcinoma (OSCC), including a correlation with some histopathological findings (tumor size, lymph node invasion and degree of tumor differentiation).

PATIENTS AND METHODS

The patients (n = 91) and the controls (n = 81) were matched by age, sex, ethnicity and smoking habits. The molecular analysis was carried out using Polymerase Chain Reaction-Restrict Length Polymorphisms PCR-RFLP (CYP1A1) and Multiplex-PCR (GSTM1/GSTT1).

RESULTS

No association was found for any of the studied genes: CYP1A1 (odds ratio (OR) = 1.24; 95% Confidence Interval (CI) = 0.67-2.31), GSTM1 (OR = 0.61; CI 95% = 0.33-1.11), and GSTT1 (OR = 1.24; CI 95% = 0.65-2.38). The analysis of combining genotypes also showed lack of association. Comparison with the histopathological findings did not, in general, detect any statistically significant differences.

CONCLUSION

CYP1A1, GSTM1 and GSTT1 polymorphisms do not appear to influence the genetic susceptibility to OSCC or the progression to more advanced stages.

Subclinical pituitary microadenomas

To analyze the incidence as well as the natural history of asymptomatic pituitary microadenomas, 450 pituitary glands obtained during routine autopsies were studied. The series consisted of patients of both sexes, without any evidence of pituitary dysfunction, in a broad age range. Thirty-nine tumors were found in 36 pituitary glands, with a peak incidence in the seventh decade of life and an evident predominance in male patients. The medical records and available x-ray films of the skull of these patients with subclinical microadenomas were reviewed for clinical evidence of endocrinopathy and to detect minor radiologic abnormalities of the sella turcica. No significant differences were found in comparing the histologic aspect of these tumors with symptomatic cases. The possibility of these tumors as a preclinical stage of pituitary adenoma or a separate entity is discussed.