HRM screening of the UBC9 gene encoding the SUMO-E2-conjugating enzyme - case-control study in breast cancer.

AIM: UBC9 (E2) small ubiquitin-like modifier conjugating enzyme plays a key role in the post-translational modification of proteins named sumoylation. Defects in small ubiquitin-like modifier modification may contribute to breast carcinogenesis. In the present work, we examined UBC9 genetic variation. MATERIALS AND METHODS: UBC9 genetic variation was analyzed by using the high resolution melting (HRM) method. HRM study was conducted on 173-182 healthy women and 188-190 women with breast cancer. RESULTS: During HRM screening, we analysed three known single-nucleotide polymorphisms in introns: rs4984806, rs909916 and rs909917, and one known single nucleotide polymorphism rs8063 in exon 7, in a non-coding region. The genotype frequencies for all polymorphisms were in accordance with Hardy - Weinberg equilibrium among the control subjects and breast cancer patients. The linkage disequilibrium analysis displayed that there was one polymorphism block, which consisted of three single nucleotide polymorphisms: rs909916, rs909917 and rs4984806. We identified two common haplotypes CCG and TTC, but we did not find significant differences in the distribution of these haplotypes between cases and controls. CONCLUSION: Our study showed no differences in the occurrence of indicated polymorphisms in the UBC9 gene in a group of healthy women compared to women with breast cancer. These results suggest that the polymorphisms of the UBC9 gene - rs4984806, rs909916, rs909917 and rs8063 can be not associated with breast cancer risk.

Immune checkpoints in aggressive breast cancer subtypes.

Immune checkpoints are molecules referred to inhibitory pathways in the immune system that play a pivotal role in prevention of autoimmunity and oncogenesis. The aim of the study was to evaluate expression levels of selected immune checkpoints- PD-1 (programmed cell death protein 1), and PD-L1 (programmed cell death 1 ligand 1) in breast cancer patients, suitable for breast conservation and sentinel node biopsy and determine their associations with clinicopathological factors.Expression of the genes coding for PD-1 and PD-L1 was analyzed in formalin-fixed paraffin-embedded specimens using real-time PCR. mRNA expression levels were determined using beta actin (ACTB) as an endogenous control. There was a trend towards significance between higher PD-1 and PD-L1 levels in triple negative breast cancers (p=0.1). Higher PD-L1 expression was also found in aggressive breast cancer subtypes e.g. triple negative and HER2 (human epidermal growth factor receptor 2) -positive as compared with subtypes with better prognosis such as luminal A and luminal BHER2-negative (p=0.05). There was a trend towards significance in higher PD-1 levels in triple negative and HER-2 positive breast cancers (p=0.1). A statistically significant difference was found between PD-L1 expression and tumor grade (p=0.01). Elevated PD-L1 levels were noted in G3 tumors. Immunogenicity appears to be gaining importance in triple negative and HER2-positive molecular subtypes of breast cancer, and the results in this study provide a basis for further investigation into the role of immune checkpoints in breast cancer.

The impact of oophorectomy on survival after breast cancer in BRCA1-positive breast cancer patients.

The aim of the study is to identify treatments which predict survival for women with a BRCA1 mutation, including oophorectomy and chemotherapy. 476 women with stage I to stage III breast cancer who carried a BRCA1 mutation were followed from diagnosis until April 2015. Information on treatment was obtained from chart review and patient questionnaires. Dates of death were obtained from the Poland vital statistics registry. Survival curves were compared for different subgroups according to treatment received. Predictors of overall survival were determined using the Cox proportional hazards model. The ten-year overall survival was 78.3 % (95 % CI 74.2-82.6 %) and the ten-year breast cancer-specific survival was 84.2 % (95 % CI 80.5-88.0 %). Sixty-two patients died of breast cancer, 14 patients died of ovarian cancer, and 2 patients died of peritoneal cancer. Oophorectomy was associated with a significant reduction in all-cause mortality in the entire cohort (adjusted HR = 0.41; 95 % CI 0.24-0.69; p = 0.0008) and in breast cancer-specific mortality among ER-negative breast cancer patients (HR = 0.44; 95 % CI 0.22-0.89; p = 0.02). Among women with breast cancer and a BRCA1 mutation, survival is greatly improved by oophorectomy due to the prevention of deaths from both breast and ovarian cancer.

Dendrimers in therapy for breast and colorectal cancer.

Current trends in research dealing with methods of developing effective chemotherapy for the two most dangerous killers - breast and colon cancers have been discussed. The input brought by nanotechnology is presented with particular stress on the use of dendrimers. These unique "polymeric compounds" after modification can form intelligent species, transporting drugs into specific areas and at the same time can be used for monitoring the state of organs attacked by cancer cells, as well as the progress of the curing process. They can help to limit the anticancer drugs delivery to designed goals only, eliminating many side effects of chemotherapy. Breast and colon cancer are major problem for public health care in many countries all over the world. During last twenty years a dramatic increase in incidence of both of them has been observed, especially in industrialized countries. Probably, both of them are caused, apart from the hereditary syndromes, by specific point mutation, some hormonal factors in breast cancer and by the strong co-influence of environmental factors and dietary exposure of a patient.

Apoptosis-, proliferation, immune function-, and drug resistance- related genes in ER positive, HER2 positive and triple negative breast cancer.

The aim of our study was to examine an association between gene expression assessed using a 23-gene microarray and receptor status of breast cancer samples categorized as ER positive, HER2 positive and triple negative subtypes. The ER positive cohort was subsequently divided into Luminal A, Luminal B HER2 negative and Luminal B HER2 positive subtypes. Core- needle biopsies were collected from 78 female patients with inoperable locally advanced breast cancer or resectable tumors suitable for downstaging, before any treatment. Expressions of 23 genes were determined by means of TagMan Low Density Arrays. Analysis of variance was used to select genes with discriminatory potential between receptor subtypes. We introduced a correction for false discovery rates (presented as q values) due to testing multiple hypothesis. Pairwise post-hoc comparisons of receptor subtypes were performed using Tukey 's HSD test. Five genes out of a 23-gene microarray differed significantly in relation to breast cancer receptor-based subtypes. Among these five genes, we identified: BCL2 (p=0.0002, q=0.0009), MKI67 (p=0.0037, q=0.0064), IGF1R (p=0.0040, q=0.0064), FOXC1 (p=0.0113, q=0.0135) and IRF1 (p=0.0435, q=0.0416) as ones showing ER positive, HER2 positive and triple negative -subtype specific expression profiles. When incorporating Luminal A, Luminal B HER2 negative, Luminal B HER2 positive subtypes into analysis, four genes: BCL2 (p=0.0006, q=0.0034), MKI67 (p=0.0078, q=0.0198), FOXC1 (p=0.0102, q=0.0198) and IGF1R (p=0.0174, q=0.0254) were selected. Elevated levels of IGF1R and BCL2 were significantly linked with Luminal A subtype. Triple negative breast cancer subtype was associated with higher expression of IRF1, FOXC1 and MKI67. In HER2 positive cohort lower expression of all five analyzed genes was noted.

Association between polymorphisms of the BRCA2 gene and clinical parameters in breast cancer.

BACKGROUND: A C/T transition - rs4987117 (the Thr1915Met polymorphism) and an A/G transition - rs11571653 (the Met784Val polymorphism) in the BRCA2 gene were linked to breast cancer risk in Polish and Japanese populations, respectively. AIM: To study the association between polymorphisms of the BRCA2 gene and clinical parameters in breast cancer. METHODS: Both polymorphisms were evaluated by RFLP - PCR in blood samples obtained from 117 women with sporadic breast cancer. Patients were stratified by genotype, Bloom - Richardson grade, TNM stage, estrogene and progesterone receptors (PR) status and the linkages of each genotype with each stratum were calculated by logistic regression. RESULTS: Variant genotypes and alleles of both polymorphisms of the BRCA2 gene were inversely related to hormone receptor status for a group of patients with at least one positive receptor status as compared to a group with both receptors negative status (OR 0.27, 95% CI 0.07 - 0.95, p = 0.043 and OR 0.39, 95% CI 0.19 - 0.82, p = 0.013 for Met1915Met homozygote and 1915Met allele, respectively and OR 0.02, 95% CI 0.00 - 0.13, p = 0.0005 and OR 0.43, 95% CI 0.21 - 0.88, p = 0.021, for Val784Val homozygote and the 784Val allele. No association was found between both polymorphisms and Bloom - Richardson grading and TNM staging. CONCLUSIONS: Our results suggest that variant genotypes of the Thr1915Met and Met784Val polymorphisms of the BRCA2 gene may be indicative factors in therapy of ductal breast cancer.

No association between the Arg194Trp and Arg399Gln polymorphisms of the XRCC1 gene and colorectal cancer risk and progression in a Polish population.

BACKGROUND: The risk of sporadic colorectal cancer can be associated with environmental and lifestyle factors that may be sources of physical and chemical carcinogens, modulated by products of many low penetrance genes. Polymorphisms of DNA repair genes may influence variation in individual DNA repair capacity, which is crucial for preventing genomic instability, which, in turn, may be associated with risk of cancer. XRCC1 is an essential protein for the base excision repair pathway which primarily deals with DNA base modifications, arisen spontaneously or as a consequence of the action of environmental factors. AIM: To perform a case-control study and test the association between two polymorphisms in the XRCC1 gene: Arg194Trp and Arg399Gln and colorectal cancer risk and progression. METHODS: Genotypes were determined in DNA from peripheral blood lymphocytes of 100 colorectal cancer patients and 100 age, sex and ethnic-matched cancer-free controls by PCR RFLP. RESULTS: We found that both polymorphisms of the XRCC1 gene were not associated with risk and progession of colorectal cancer in a Polish population. Moreover, there was not such association form the Arg194Trp/Arg399Gln haplotypes. CONCLUSION: The Arg194Trp and Arg399Gln polymorphisms of the XRCC1 gene may not be associated with colorectal cancer in Polish population.

Promoter methylation of cancer-related genes in gastric carcinoma.

UNLABELLED: Genetic changes associated with gastric cancer are not completely known, but epigenetic mechanisms involved in this disease seem to play an important role in its pathophysiology. One of these mechanisms, an aberrant methylation in the promoter regions of genes involved in cancer induction and promotion, may be of particular importance in gastric cancer. AIM: To analyze the methylation status of eight genes: Apaf-1, Casp8, CDH1, MDR1, GSTP1, BRCA1, hMLH1, Fas in gastric cancer patients. METHODS: The methylation pattern of the genes was assessed by methylation specific restriction enzyme PCR (MSRE-PCR) in gastric tumors taken during surgery of 27 patients and compared with the methylation pattern in material obtained from biopsy in 25 individuals without cancer and pre-cancerous lesions. RESULTS: We observed a promoter hypermethylation in the Casp8, hMLH1, CDH1 and MDR1 in gastric cancer patients as compared with the controls. Additionally, we investigated the relationship between promoter hypermethylation and age, gender, smoking and gastric cancer family history. The hypermethylation of the hMLH1 gene occurred more frequently in female than in men, and the hypermethylation of the CDH1 gene was observed preferentially in smoking than in non-smoking individuals. CONCLUSION: The data obtained indicate that changes in DNA methylation may contribute to gastric carcinogenesis.

Amifostine can differentially modulate DNA double-strand breaks and apoptosis induced by idarubicin in normal and cancer cells.

UNLABELLED: We have previously shown that amifostine differentially modulated the DNA-damaging action of idarubicin in normal and cancer cells and that the presence of p53 protein and oncogenic tyrosine kinases might play a role in this diversity. AIM: To investigate further this effect we have studied the influence of amifostine on idarubicin-induced DNA double-strand breaks (DSBs) and apoptosis. METHODS: We employed pulse-field gel electrophoresis () for the detection of DSBs and assessment of their repair in human normal lymphocytes and chronic myelogenous leukaemia K562 cells lacking p53 activity and expressing the BCR/ABL tyrosine kinase. Apoptosis was evaluated by caspase-3 activity assay assisted by the alkaline comet assay and DAPI staining. RESULTS: Idarubicin induced DSBs in a dose-independent manner in normal and cancer cells. Both types of the cells did not repair these lesions in 120 min and amifostine differentially modulated their level - decreased it in the lymphocytes and increased in K562 cells. In contrast to control cells, amifostine potentated apoptotic DNA fragmentation, chromatin condensation and the activity of caspase-3 in leukaemia cells. CONCLUSION: Amifostine can differentially modulate DSBs and apoptosis induced by idarubicin in normal and cancer cells. It can protect normal cells against drug-induced DNA damage and it can potentate the action of the drug in leukaemic cells. Further studies on link between amifostine-induced modulation of DSBs and apoptosis of cancer cells will bring a deeper insight into molecular mechanism of amifostine action.

An association between the matrix metalloproteinase 1 promoter gene polymorphism and lymphnode metastasis in breast cancer.

A single guanine insertion (1G/2G polymorphism) in the promoter of the matrix metalloproteinase (MMP-1) gene creates a binding site for the transcription factor and may affect the level of transcription of MMP-1. An elevated level of MMP-1 in cancer cells may facilitate their invasion and contribute to metastasis. To evaluate the contribution of 1G/2G polymorphism in the development and/or progression of breast cancer we genotyped 135 subjects with breast cancer. The 1G/2G polymorphism was determined by the method based on restriction endonuclease digestion. We found that the frequency of the 2G allele was higher in lymphnode-metastasis patients than in the group without metastasis (p < 0.001). We did not find differences between distribution of the genotypes and frequencies of alleles in cancer patients and in healthy subjects served as control. Our results suggest that allele 2G may be associated with lymphnode metastasis in patients with breast cancer and therefore it can be considered as a prognostic marker in this disease.