Breast cancer is the most common neoplasm affecting women in the Western world. Many studies are still conducted with the purpose of finding markers that could be used for early diagnosis and/or ...serve as possible reliable prognostic or predictive parameters, but with conflicting results. At present, no markers are available for an early diagnosis of breast cancer For surveillance of patients with diagnosed breast cancer the most widely used serum markers are CA 15-3 and CEA which, in combination with other clinical parameters, could have clinical significance. The most useful and clinically important tissue-based markers in breast cancer are estrogen and progesterone receptors, used as a basis for hormonal therapy, and HER-2 receptors, essential in selecting patients for the treatment with Herceptin. New or potentially new markers for breast cancer include BRCA1 and BRCA2 genes for selecting patients at high risk of developing hereditary breast cancer, as well as urokinase plasminogen activator and inhibitor for assessing prognosis in lymph node-negative patients. Results of tumor and patient genetic analyses including their clinical evaluation will enable application of more individualized and personalized approach in diagnosis and therapy of breast cancer patients.
In this study we investigated the types and role of different genetic changes of PTCH1 gene in three different types of ovarian tumors: carcinomas, fibromas and dermoids. LOH of the PTCH1 region was ...detected in 27.3% ovarian carcinoma samples, 18.18% ovarian fibroma samples and 55.56% ovarian dermoid samples. No point mutations were detected in any of the three types of ovarian tumors. SNP c.3944C>T showed significant differences between ovarian carcinoma and control samples with the minor T allele being significantly higher in controls compared to ovarian carcinomas. Interestingly, a new polymorphism c.−1184G>A was found only in tumor samples and further analyses should be performed in order to elucidate its potential role in ovarian tumors.
► LOH of PTCH1 region was detected in 27.3% OC, 18.2% OF and 55.6% OD samples. ► No point mutations were detected in any of the three types of ovarian tumors. ► Significant differences were found for SNP c.3944C>T between OC and control samples. ► New c.−1184G>A polymorphism was found only in tumor samples.
DNA methylation status in the CpG sites of promoter regions in cancer-related genes, such as PTCH, has traditionally been investigated using either dye-terminator sequencing or methylation-specific ...PCR. We aimed to study the PTCH gene promoter methylation in gynecological cancers, with a method that gives a quantitative measure of the methylation status of the promoter region of the studied gene, and for this purpose, we designed novel Pyrosequencing-based assays. Bisulfite-treated genomic DNA (bsDNA) was amplified by standard PCR and applied to novel Pyrosequencing® assays, in order to measure the methylated fraction (%) at each CpG site of the PTCH gene promoter. We analyzed 22 squamous cell cervical cancer tissue specimens (11 with good and 11 with poor outcomes after radiotherapy) and 5 ovarian cancer tissue specimens matched with 5 normal ovarian tissue specimens. Six optimized PCR protocols which generated 8 Pyrosequencing assays covering 63 CpG sites in the promoter regions 1 and 2 as well as the previously unanalyzed promoter region 3 in the PTCH gene were developed. The 27 tumor tissue specimens and 5 normal tissues did not show any methylation within any of the 63 CpG sites. Our data suggest that methylation of the PTCH promoter is not a high-prevalence feature of squamous cell cervical cancer or ovarian cancer, but Pyrosequencing assays are a good method for studying promoter methylation.
BRCA1 and BRCA2 genes from 167 candidates (145 families) were scanned for mutations. We identified 14 pathogenic point mutations in 17 candidates, 9 in BRCA1 and 5 in BRCA2. Of those, 11 have been ...previously described and 3 were novel (c.5335C>T in BRCA1 and c.4139_4140dupTT and c.8175G>A in BRCA2). No large deletions or duplications involving BRCA1 and BRCA2 genes were identified. No founder mutations were detected for the Croatian population. Croatia shares most of the mutations with neighboring Slovenia and also with Germany, Austria and Poland.
Two common sequence variants in BRCA1, c.2077G>A and c.4956G>A, were found more frequently in mutation carriers compared to healthy controls. No difference in BRCA2 variants was detected between the groups.
Haplotype inference showed no difference in haplotype distributions between deleterious mutation carriers and non-carriers in neither BRCA1 nor BRCA2. In silico analyses identified one BRCA1 sequence variant (c.4039A>G) and two BRCA2 variants (c.5986G>A and c.6884G>C) as harmful with high probability, and inconclusive results were obtained for our novel BRCA2 variant c.3864_3866delTAA.
Combination of QMPSF and HRMA methods provides high detection rate and complete coverage of BRCA1/2 genes. Benefit of BRCA1/2 mutation testing is clear, since we detected mutations in young unaffected women, who will be closely monitored for breast and ovarian cancer.
► QMPSF and HRMA provide high detection rate and complete coverage of BRCA1/2 genes. ► 14 pathogenic point mutations in 17 candidates, 9 in BRCA1 and 5 in BRCA2. ► Three novel mutations: BRCA1 c.5335C>T; BRCA2 c.4139_4140dupTT and c.8175G>A. ► BRCA1 c.2077G>A and c.4956G>A variants are more frequent among mutation carriers. ► In silico analysis confirmed BRCA2 mutation c.9371A>T pathogenic character.
The involvement of two tumor suppressors p16 and Ptch in pathogenesis of cutaneous melanomas and basal cell carcinomas (BCCs) was studied through expression of Ptch and p16 and genetic alterations in ...9p21 region (p16) and in 9q22.3 region (PTCH) of chromosome 9. Immunohistochemical analyses of paraffin-embedded tissues with Ptch and p16 antibodies, typing for 9q22-q31 and 9p21 region with polymorphic markers and p16 and Ptch mutation detection was done. Higher expression of p16 and Ptch in melanoma and BCC of the skin was frequently detected in studied cases. However, allelic loss of PTCH region occurs more frequently in BCCs than loss of heterozygosity of p16 region. Both types of tumors, BCCs and melanomas, suggest involvement of Hh-Gli signaling pathway, but using different mechanisms.
Background: Mutations in BRCA1 and BRCA2 genes are associated with family predisposition to breast and ovarian cancer. Novel screening methods are required for efficient and rapid detection of ...sequence variants in cancer patients and their family members. Methods: The screening for variants in the breast and ovarian cancer susceptibility genes BRCA1 and BRCA2 in Croatia was performed by a high-resolution melting approach, which is based on differences in melting curves caused by variations in nucleotide sequence. This is the first screening in Croatia on elderly healthy women with no family history of cancer. BRCA1 screening was performed on 220 and BRCA2 screening on 115 samples. Results: In a population well beyond the average age of breast/ovarian cancer onset, 21 different sequence variants in the BRCA1 gene (one novel: c.5193+49_50delTA) and 36 variants in the BRCA2 gene (7 novel: c.459A>C, c.3318C>A, c.4412_ 4414delGAA, c.4790C>A, c.6264T>C, c.9087G>A, and c.9864A>G) were detected. Conclusions: Nine BRCA1 and seven BRCA2 known variants appeared with such high frequencies that they could be declared as harmless in this population. Eight BRCA1 high frequency variants, located further from the promoter region, appear to be strongly correlated. Three novel variants that changed the amino acid sequence of the BRCA2 protein (two missense base substitutions, c.3318C>A and c.4790C>A, and one codon deletion c.4412_4414delGAA), appearing only once, were predicted to have no potential effect on protein structure and function. Clin Chem Lab Med 2008;46:1376–83.
We report a case of a 53-year-old woman with Grade 1 serous cystadenocarcinoma on her left ovary and metastatic serous adenocarcinoma on her right ovary. Serous carcinoma is the most common type of ...ovarian cancer, representing approximately half of all cases. Because of positive family history, the patient was referred for BRCA1/2 screening. Germline BRCA1 mutation c.676delT (p.C226VfsX8) was found, and in tumor tissue the normal allele was lost. Tumor tissue also had loss of heterozygosity in the PTCH1 gene, one of the major members of the Hedgehog-Gli (Hh-Gli) pathway. Gene expression analysis showed upregulation of the Hh-Gli pathway in both ovaries compared with healthy ovarian tissue. Primary cell culture was developed from the patient's tissue and showed downregulation of gene expression in response to cyclopamine, a Hh-Gli pathway inhibitor. The Hh-Gli signaling pathway may play a role in malignant transformation and metastasis of ovarian cancer.
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