The rs1803274 polymorphism of the BCHE gene is associated with an increased risk of coronary in-stent restenosis.

BACKGROUND: We sought to identify gene polymorphisms that confer susceptibility to in-stent restenosis after coronary artery bare-metal stenting in a Central European population. METHODS: 160 controls without post-percutaneous coronary intervention in-stent restenosis were matched for age, sex, vessel diameter, and diabetes to 160 consecutive cases involving in-stent restenosis of the target lesion within 12 months. Using real time polymerase chain reaction and melting-curve analysis, we detected 13 single-nucleotide polymorphisms in 11 candidate genes - rs1803274 (BCHE gene), rs529038 (ROS1), rs1050450 (GPX1), rs1800849 (UCP3), rs17216473 (ALOX5AP), rs7412, rs429358 (ApoE), rs2228570 (VDR), rs7041, rs4588 (GC), rs1799986 (LRP1) and rs2228671 (LDLR). Multivariable logistic regression was used to test for associations. RESULTS: The rs1803274 polymorphism of BCHE was significantly associated with in-stent restenosis (OR 1.934; 95 % CI: 1.181-3.166; p = 0.009). No association was found with the other studied SNPs. CONCLUSIONS: The A allele of rs1803274 represents a risk factor for in-stent restenosis in Central European patients after percutaneous coronary intervention with bare-metal stent implantation.

Cluster of patients with Familial Mediterranean fever and heterozygous carriers of mutations in MEFV gene in the Czech Republic.

Familial Mediterranean fever (FMF) is a well-described monogenic autosomal recessive disorder with highest occurrence in the Mediterranean region. In this article, we describe the experience of a center in the Czech Republic that follows four families with members bearing mutations in MEFV gene without provable ancestry from the Mediterranean region. We also discuss the clinical picture of the heterozygous variants that were present in our cohort. The typical clinical presentation in heterozygotes corresponds to data described in the international literature. The possibility of combination of mutations and/or polymorphisms in different genes and epigenetic or environmental influences on the clinical symptoms are taken into account.

[Breast cancer in monozygotic twins]. / Karcinom prsu u monozygotních dvojcat.

SUMMARY: Breast cancer is a multifactorial disease. Twin studies comparing the disease concordance rate in identical twin pairs serve to differentiate the influence of genetic and environmental factors in the disease development. AIM OF THE STUDY: To assess breast cancer risk for an identical twin sister of a patient with breast cancer. PATIENTS AND METHODS: Five monozygotic twin families were examined during 2005- 2011 in which at least one of the monozygotic sisters developed breast cancer.In 4 breast cancer women from 4 families, molecular genetic analysis of BRCA1 and BRCA2 genes was performed. RESULTS: The median followup period was 12.6 years (7 to 24 years). No pair of monozygotic sisters was concordant for breast cancer. Familial breast/ ovarian cancer syndrome due to BRCA1 gene mutation was confirmed in one pair. These twins were phenotypically discordant, the first one developing breast cancer at the age of 54 years, her co sister suffering from ovarian cancer at the age of 43 years. In the other 4 nonBRCA families, breast cancer was diagnosed at the age of 38- 50 years (median 44 years) in one of the sisters; the other twins remain healthy through the followup period. CONCLUSION: We did not observe concordance for breast cancer in 5 pairs of monozygotic twins. Based on results of published studies, the life  time breast cancer risk for a healthy identical twin of a breast cancer nonBRCA woman is around 20- 30 %. Other nonhereditary risk factors must exist to explain the discordant phenotype. This highlights that environmental factors play an important role in breast cancer development. In case of BRCA associated breast cancer, breast cancer risk for the healthy co twin is the same as that for other BRCA mutation carriers, i.e. 45- 85%.

[Hereditary leiomyomatosis and renal cell cancer - HLRCC/multiple cutaneous and uterine leimomyomatosis - MCUL]. / Hereditární leiomyomatóza a renální karcinom - HLRCC / Mnohocetná kozní a delozní leiomyomatóza - MCUL.

Hereditary leiomyomatosis and renal cell cancer / multiple cutaneous and uterine leimomyomatosis is a relatively rare autosomal dominant condition which predisposes to the development of cutaneous and uterine leiomyomas and early-onset renal cell carcinoma, typically papillary carcinoma type II. It is caused by germline mutations in the FH gene encoding the fumarate hydratase enzyme. The test of fumarate hydratase activity in lymphocytes may be used as a screening method with subsequent mutation analysis of the FH gene in persons with reduced enzyme activity. Persons with this syndrome should be followed to detect any occurrence of these diseases. Treatment of renal cancer associated with the hereditary leiomyomatosis and renal cell cancer syndrome should be radical with respect to its aggressive nature.

[Genetic counselling in male carriers of BRCA1 and BRCA2 gene mutations]. / Genetické poradenství u muzu nosicu mutací v genech BRCA1 a BRCA2.

BRCA1 and BRCA2 gene mutations cause hereditary breast and ovarian cancer syndrome. The disease has autosomal dominant mode of inheritance, and both genders have the same probability of inheriting the trait. However, the phenotype is different in males and females, and the risk of cancer is significantly lower in males. Although the results of some studies are conflicting, it has been clearly shown that male BRCA mutation carriers are predisposed to an increased risk of breast, prostate, pancreas and stomach cancer when compared to the ge-neral population. With respect to the routinely performed predictive testing of healthy persons in families with BRCA gene mutations, results of these studies are taken into consideration. Screening programs are offered to the patients with the goal of early detection of cancer.

CCND1 and ZNF217 gene amplification is equally frequent in BRCA1 and BRCA2 associated and non-BRCA breast cancer.

Breast cancer associated with BRCA1 and BRCA2 gene mutations differs from non-BRCA tumors in several respects. We determined whether there was any difference in CCND1 (11q13) and ZNF217 (20q13) gene amplification with respect to BRCA status. Of 40 breast cancer samples examined, 15 and 9 were from BRCA1 and BRCA2 mutation carriers, respectively, and 16 from patients without mutation. Fluorescence in situ hybridization showed that eight tumors exhibited CCND1 amplification (20%; 3 BRCA1, 3 BRCA2, 2 non-BRCA). ZNF217 amplification was observed in three of 38 cases (8%; 2 BRCA1, 1 non-BRCA). There was no significant difference in CCND1 and ZNF217 amplification between BRCA1, BRCA2 and non-BRCA tumors. CCND1 amplification was associated with decreased disease-free (P = 0.045) and overall survival (P = 0.015). BRCA1 tumors with CCND1 amplification were estrogen receptor negative, in contrast to CCND1 amplified BRCA2 and non-BRCA tumors, suggesting that concurrent CCND1 amplification and estrogen and progesterone receptor negativity may predict germline BRCA1 gene mutation. All ZNF217 amplified tumors were of the medullary histological type (P = 0.002). There was no statistical correlation between CCND1 and ZNF217 amplification and estrogen receptor, progesterone receptor, and ERBB2 expression and TNM classification. CCND1 amplification did not correlate with EGFR expression.

Germline variants of the promyelocytic leukemia tumor suppressor gene in patients with familial cancer.

The promyelocytic leukemia (PML) gene is an important tumor suppressor gene. We tested the hypothesis that germline disruption of the PML gene may be associated with a cancer predisposition syndrome. Mutation analysis of the PML gene was performed in 111 patients with familial adult cancer or young age-onset adult cancer. These were mostly breast and colon cancer, or colon polyposis patients in whom mutation analyses of the BRCA1, BRCA2, MLH1, MSH2, APC or TP53 genes did not detect a pathogenic germline mutation. Heteroduplex analysis and direct sequencing were used for mutation screening. Mutation-specific methods were designed for frequency determination of novel variants in the general population. No deleterious nonsense or frameshift germline mutations were detected. Several missense single-nucleotide substitutions were found, including two novel missense variants, c.83C>T (p.Thr28Ile) in exon 1 in a 42-year-old breast cancer patient and c.1558C>T (p.Pro520Ser) in exon 6 in a 32-year-old colon cancer patient, that were not detected in 100 and 214 non-cancer persons, respectively. Frequency of the c.2260G>C (p.Ala754Pro) variant in isoform IV of the PML gene was higher in patients with colon polyposis and cancer than in the control group (P = 0.029). In conclusion, germline disruption of the PML gene is probably not associated with a highly penetrant susceptibility to adult-onset breast and colon cancer. Pathogenicity of c.83C>T and c.1558C>T variants in the PML gene is uncertain. Carriers of the c.2260 G>C variant in PMLIV isoform may be at an increased risk of colon polyposis and cancer.

[Single nucleotide c.645+32c>T substitution in the APC gene is a non-pathogenic polymorphism appearing in about 16% of the Czech population]. / Jednonukleotidová substituce c.645+32c>T v genu APC je nepatogenním polymorfismem s výskytem priblizne u 16% ceské populace.

BACKGROUND: Familial adenomatous polyposis is an autosomal dominant disease characterised by predisposition to colon polyposis and colorectal cancer and caused by germline mutations in the APC gene. The aim of the study was to establish the frequency of c.645+32C>T substitution in intron 5 of the APC gene in patients with multiple colon polyposis and in the general population and to determine if this substitution is a nonpathogenic polymorphism or a pathogenic mutation associated with multiple polyposis coli. METHODS AND RESULTS: The frequency of c.645+32C>T substitution in the APC gene was established in 170 patients with the clinical phenotype of familial adenomatous polyposis or its attenuated form using denaturating gradient gel electrophoresis and direct sequencing. We tested a population of 200 noncancer persons using allelic specific polymerase chain reaction. The c.645+32C>T substitution was detected in 27 of 170 patients with multiple colon polyposis (i.e. 15.9%). The substitution was found in 32 of 200 control persons, i.e. in 16%. The difference between patients with polyposis and the control group was not statistically significant (p = 0.979; chí-square test). CONCLUSIONS: Our results suggest that the c.645+32C>T substitution is a non-pathogenic single nucleotide polymorphism appearing in about 16% of the Czech population.

PML protein expression in hereditary and sporadic breast cancer.

The PML protein is concentrated in the PML nuclear bodies. Downregulation of the PML protein has been described in various types of cancer and is in accordance with the fact that dysqualification of tumor suppressive functions of the PML protein might promote cancer development. Various differences have been described between sporadic breast cancer and that associated with BRCA1 and BRCA2 gene mutations. Expression of the PML protein has not been studied yet. The aim of this study was to determine if there is any difference in PML protein expression in breast cancer of BRCA1 and BRCA2 gene mutation carriers compared to sporadic breast cancer and if the PML protein can be used as a prognostic marker. There were 47 breast cancer samples included, 14 and 10 from BRCA1 and BRCA2 germline mutation carriers, respectively, and 23 from patients without a BRCA1/BRCA2 germline mutation. Immunofluorescence staining was used. Downregulation of PML protein expression was found in 2 of 14 (14%), 3 of 10 (30%) and 15 of 47 (31%) cases of breast cancer samples from BRCA1, BRCA2 and no BRCA1/BRCA2 mutation carriers, respectively (p(BRCA1) = 0.019; p(BRCA2) = 0.111). There was no correlation between PML protein expression and age, histological types, estrogen and progesterone receptor, c-erbB-2 and PCNA expression, TNM classification, disease-free and overall survival. In conclusion, the PML protein is downregulated in approximately 30% of breast cancers cases. Downregulation of PML protein expression was significantly less frequent in BRCA1 mutation carriers compared to sporadic cases. No correlation was found between PML protein expression and any of the other clinical and laboratory characteristics.

PML and TRF2 protein expression in hereditary and sporadic colon cancer.

The PML (promyelocytic leukemia) protein is concentrated in the PML nuclear bodies. In human cell lines and tumors maintaining their telomeres by alternative lengthening (ALT), the PML protein is colocalized with TRF2 and several other proteins in the so called ALT-associated PML bodies. The aim of this study was to determine if there is any difference in PML protein expression between tumors with stable microsatellites (MSS) and those with high-frequency microsatellite instability (MSI-H), if PML protein expression might be a prognostic factor and if MSI-H tumors more frequently use alternative lengthening of telomeres measured by the presence of ALT-associated PML bodies. Eighty colorectal cancer samples (32 MSI-H and 48 MSS) and 8 human tumor cell lines (Saos-2, U2OS, DU145, LNCaP, U87, HeLa, MCF7 and T98G) were included into the study. Double-colour immunofluorescence staining was used. Downregulation of PML protein expression was found in 7 of 32 (22%) MSI-H and 11 of 48 (23%) MSS tumors (p=0.520). There was no correlation between PML expression and age, histological typing, localization of the tumor in colon, TNM classification, disease-free and overall survival. The Saos-2 and U2OS (ALT using cell lines) and the MCF7 (active telomerase) cell line were characterized by the presence of ALT-associated PML bodies; no such bodies were detected in the DU145, LNCaP, U87, HeLa and T98G cell lines (active telomerase); accumulation of TRF2 was absent or much weaker in these cell lines compared to Saos-2 or U2OS. Accumulation of the TRF2 protein was detected in 16 of 80 (20%) tumors and PML and TRF2 colocalization in 2 MSI-H tumors (6%). In conclusion, the PML protein was downregulated in approximately 20% of tumors; there was no difference between MSS and MSI-H tumors. PML protein expression does not seem to be a prognostic factor.

Immunohistochemical detection of the hMLH1 and hMSH2 proteins in hereditary non-polyposis colon cancer and sporadic colon cancer.

Defects in DNA mismatch repair system are involved in carcinogenesis of sporadic and inherited human cancers. We assessed the feasibility of using immunohistochemistry to detect tumors with DNA mismatch repair deficiency. We analyzed 81 samples (74 colon cancers (CC), 1 colon dysplasia and 6 extracolonic cancers) for hMLH1 and hMSH2 protein expression, microsatellite instability (MSI) and/or mutational analysis. A meta-analysis of the published data on immunohistochemistry of hMLH1/hMSH2 proteins was performed. Sensitivity and specificity of the method was calculated. Twenty four of 29 tumors from hMLH1/hMSH2 mutation carriers and 10 of 13 sporadic high frequency MSI tumors lost one of the proteins. None of the 42 tumors with stable microsatellites or low frequency MSI lost the proteins. Based on literature review of 49 publications on colorectal cancer, hMLH1 immunohistochemistry was able to detect 136 of 154 tumors from hMLH1 germline mutation carriers (the sensitivity of 88.3% [95%CI, 85.8-90.8%]), hMSH2 immunohistochemistry detected 99 of 109 tumors from hMSH2 mutation carriers (the sensitivity of 90.8% [95%CI, 88.5-93.1%]), and hMLH1/hMSH2 immunohistochemistry identified 1262 of 1382 tumors with high-frequency microsatellite instability not correlated with mutational analysis (the sensitivity of 91.3% [95%CI, 90.4-92.2%]). The specificity of the method was 99.4% (95%CI, 99.2-99.6%). In conclusion, immunohistochemistry of hMLH1 and hMSH2 proteins is a useful method to predict the presence of mismatch repair deficiency, although its sensitivity is lower than that of MSI analysis.

Familial adenomatous polyposis as a precancerosis of colon cancer.

Familial adenomatous polyposis is a genetic disorder caused by mutations of the adenomatous polyposis coli gene. This gene is localized on chromosome 5q21. The incidence of the disease is 1/7000-8000. Surgery has an important role in the management of familial adenomatous polyposis. In the absence of prophylactic colectomy, death from colom cancer will occur in virtually all of familial adenomatous polyposiscases by age 50, with 37% affected by colon cancer by age 37. (Ref. 8).