[Recommended Extension of Indication Criteria for Genetic Testing of BRCA1 and BRCA2 Mutations in Hereditary Breast and Ovarian Cancer Syndrome]. / Doporucení rozsírení indikacních kriterií ke genetickému testování mutací v genech BRCA1 a BRCA2 u hereditárního syndromu nádoru prsu a ovarií.

Genetic testing for hereditary breast and ovarian cancer syndrome is indicated by a genetic counselor on the basis of personal and family history evaluation, with regards to consensual criteria, reflecting the current knowledge. The latest recommendation accepted by Czech Oncology Society and Society of Medical Genetics was published in the supplement 22 to the Journal of Clinical Oncology in 2009. Since the availability of PARP inhibitors for treatment of ovarian cancer in BRCA1/ 2 mutation carriers, an update of these guidelines is urgently needed. Another reason is a higher incidence of other malignancies in high-risk families, such as prostate or pancreatic cancer. The goal is to refine the detection of mutations in selected families, to improve preventive care and collect data necessary for targeted cancer treatment.

[Retrospective NGS Study in High-risk Hereditary Cancer Patients at Masaryk Memorial Cancer Institute]. / Retrospektivní NGS studie u vysoce rizikových pa-cientu s hereditární predispozicí k nádorovému onemocnení v Masarykove onkologickém ústavu.

BACKGROUND: Currently, more than 200 hereditary cancer syndromes have been described, yet, in most countries genetic testing is restricted to a narrow spectrum of genes within a limited group of people tested. METHODS: For this retrospective study we used the TruSight cancer panel (Illumina)--NGS panel targeting 94 cancer predisposition genes in order to analyze 50 high-risk cancer patients with significant personal and family history of cancer who did not carry mutations in BRCA1, BRCA2, MLH1, MSH2, MSH6, TP53 or APC genes. All pathogenic and potentially pathogenic mutations detected by NGS technology have been confirmed by Sanger sequencing. RESULTS: There were several deleterious (frame-shift/nonsense) mutations detected in ATM, BAP1, FANCC, FANCI, PMS2, SBDS, ERCC2, RECQL4 genes. Various pathogenic or potentially pathogenic (missense, predicted splice site, in-frame insertion/deletion) mutations were detected in ATM, BRIP1, CDH1, CHEK2, ERCC2, ERCC3, ERCC4, FANCA, MC1R, MEN1, MRE11A, MUTYH, PALB2, RAD51C, RET, SDHB, STK11. These mutations affect highly conserved protein domains and affect their function as proved by the available functional assays. They were confirmed to be pathogenic as an "Parent No2 " in serious recessive diseases such as Ataxia telangiectasia or Fanconi anemia. The clinical significance of the majority of detected missense variants still remains to be identified. CONCLUSION: Moderate or low penetrance variants are of limited clinical importance. Panel genetic testing in high-risk individuals with cancer provides important information concerning the cause of the investigated cancer, and may assist in the risk assesment and optimal management of the cancer, as well as in further preventive care.

[Importance of uroflowmetry in lower urinary tract symptoms diagnostics]. / Význam uroflowmetrie v diagnostice poruch dolních mocových cest.

OBJECTIVE: To summarize the current state of knowledge on the use of uroflowmetry in diagnosis of lower urinary tract dysfunction in women. DESIGN: Review article. SETTING: Department of Obstetrics and Gynecology, University Hospital Ostrava and Faculty of Medicine, Ostrava University. METHODS: Literature review. RESULTS AND CONCLUSION: Lower urinary tract dysfunction is associated with debilitating symptoms, which negatively affect the quality of life of a large number of patients, and represent a significant health problem. Inaccurate diagnosis leads to delayed therapy, which could cause disease progression and complications. It has been recently recognized that affected patients express a wide variety of clinical phenotypes. Advancements in diagnostic procedures may allow for individualized treatment and improved treatment outcomes. Diagnostic procedures recommended for patients with suspected lower urinary tract disease include directed medical history, urinalysis, voiding diary, as well as non-invasive and invasive urodynamic methods. Additional diagnostic tests may be used in select cases. Uroflowmetry is a basic urodynamic method used for screening. It represents a standard component used in the diagnostic process for patients with lower urinary tract symptoms. Sonouroflowmetry is a new method, which evaluates the urinary flow and lower urinary tract symptoms in a non-invasive manner by analysing the sound generated by a stream of urine striking the water surface in the toilet bowl.

[The risk factors for pelvic floor trauma following vaginal delivery]. / Rizikové faktory poskození svalu pánevního dna v souvislosti s vaginálním porodem.

OBJECTIVE: The evaluation of the risk and protective factors for pelvic floor trauma in relation to vaginal delivery. DESIGN: Review. SETTING: Department of Obstetrics and Gynecology, University Hospital of Ostrava. METHODOLOGY AND RESULTS: The aim was to provide a comprehensive survey of studies focused on risk factors for pelvic floor trauma following vaginal delivery; and to constitute the relationship between the risk and protective factors and levator ani injury. To state the prognosis of the pelvic floor injury before a child delivery is difficult and almost impossible, but it has been assumed that an operative vaginal delivery (obstetrical forceps) represents a significant risk factor for avulsion. The change in obstetric practice can prevent the injury and thus to reduce an adverse effect. CONCLUSIONS: Pregnancy and the methods of childbirth are important factors with an impact on pelvic floor injury, potentially contributing to the development of pelvic organ prolapse, and stress and anal incontinence. The recognition of the factors, the proper training of medical staff in the management of labour, and subsequently the proper treatment of perineal tears should prevent pelvic floor injury.

[Vacuum-assisted vaginal delivery does not significantly contribute to the higher incidence of levator ani avulsion]. / Vaginální porod s pouzitím vakuumextraktoru není spojen se signifikantne vyssím výskytem avulzního poranení levátoru

OBJECTIVE: To draw a comparison between spontaneous vaginal delivery and vacuum-assisted vaginal delivery in relation to the incidence and the type of levator ani avulsion in primiparas. DESIGN: Retrospective observational study. SETTIMG: Department of Obstetrics and Gynaecology, University Hospital of Ostrava. METHODOLOGY: In the study, the primiparas who were from 6 to 12 months after spontaneous vaginal delivery (group A, n = 52) or after childbirth with vacuum extraction (group B, n = 51) underwent translabial 3D ultrasound. The obstetric data had been obtained from the hospital database. Translabial 3D ultrasound examination were performed by two sonographists. The monitored parameter was the distance between urethra and fibres of musculus levator ani - levator urethra gap [6]. The distance longer than 25 mm was considered an avulsion injury [6, 22]. Other parameters assessed in relation to the avulsion were: women's age, BMI, epidural analgesia, episiotomy performance, the length of the first and the second stages of labour, and fetal weight. RESULTS: Musculus levator ani avulsion was diagnosed in 10 women - unilateral in 8 cases and bilateral in 2 cases. In group A, women after spontaneous birth, we noticed avulsion injury in 7.7% of cases, whereas in group B, women after vacuum extraction, we recorded avulsion injury in 11.8% of cases. Thus the use of vacuum extraction is not statistically significant risk factor for avulsion musculus levator ani. Statistically significant difference in comparison group A and B was recorded in BMI, the length of the second stages of labour and episiotomy performance. CONCLUSION: We did not prove a statistically significant connection between avulsion injury and delivery with the use of vacuum extraction in comparison to avulsion injury incidence in uncomplicated vaginal delivery group (tab. 1). Vacuum extraction does not appear as a risk factor for avulsion in contrast to forceps delivery.

[Intraindividual variability of uroflowmetry in women]. / Intraindividuální variabilita uroflowmetrického vysetrení u zen.

OBJECTIVE: The objective of this study was to determine the intraindividual variability of uroflowmetric measurement in women with normal lower urinary tract function. DESIGN: Prospective study. SETTING: Departure of obstetrics and gynecology University Hospital and Medical Faculty Ostrava. METHODS: 35 women without lower urinary tract dysfunction were enrolled into the study. Every subject uderwent 3 uroflowmetric examinations. We processed all numeric results. RESULTS: We assessed maximum and average urine flow rate - Qmax, Qave, voided volume - VV, corrected maximum urine flow and corrected average urine flow rate in every of 105 uroflowmetric´s measurements. We did not find any statistically significant difference for evaluation of intraindividual dispersion in studied parameters. CONCLUSION: Intraindividual variability of uroflowmetric´s measurement in healthy female subjects is low. One uroflowmetric´s measurement is adequate for assessment of uroflowmetric´s parameters.. KEYWORDS: uroflowmetry, intraindividual variability, lower urinary tract.

Respiratory failure in a term newborn due to compound heterozygous ABCA3 mutation: the case report of another lethal variant.

Inherited disorders of surfactant metabolism are manifested in neonatal period as a severe respiratory failure not responding to exogenous surfactant administration. We illustrate the case of a term newborn with respiratory failure because of compound heterozygous mutation in adenosine triphosphate-binding cassette transporter A3 (ABCA3)-in exon 24 M1227R and in exon 29 Ins1510fs/ter1519. These mutations of ABCA3 have not been described yet and expand the group of lethal ABCA3 variants.

[Li-Fraumeni syndrome - a proposal of complex prevention care for carriers of TP53 mutation with total-body MRI]. / Li-Fraumeni syndrom - návrh komplexní preventivní péce o nosice TP53 mutace s pouzitím celotelové magnetické rezonance.

Li-Fraumeni syndrome (LFS) is one of the most serious hereditary cancer syndromes with high risk of malignancy already in childhood. Adrenocortical carcinoma, brain tumor, leukemia, sarcoma are the most frequent malignancies in children. Early breast cancer, brain tumor, sarcoma, skin cancer, gastrointestinal, lung, gynecological, hematological and other malignancies can be seen in adults. Predictive testing in families with detected LFS and TP53 mutation is offered from the age of 18 for various reasons. One of the most important reasons is a very limited effectivity of prevention especially in children, also the possible risk of psychological harm to the child and his family caused by the diagnosis of this syndrome. Progress in diagnostic methods, especially total body MRI, enables to propose preventive care for early cancer diagnoses for children and adults. Biochemical tests, ultrasound, MRI may improve survival of these high risk individuals and support the possibility of predictive testing in children.

[The clinical importance of a genetic analysis of moderate-risk cancer susceptibility genes in breast and other cancer patients from the Czech Republic]. / Klinický význam analýz genu stredního rizika pro hodnocení rizika vzniku karcinomu prsu a dalsích nádoru v Ceské republice.

BACKGROUND: Analysis of the major breast cancer (BC) predisposition genes BRCA1 and BRCA2 enables identification of high-risk individuals. Specialized programs enrolling the carriers of BRCA1/2 mutations facilitate an improvement in prevention and early diagnostics in asymptomatic individuals and rationalize the selection of individualized treatment in case of a BC onset. However, the carriers of mutations in the major predisposition genes represent only approximately 25% of cases among high-risk BC patients. Numerous candidate predisposing genes for breast and other cancers have recently been identified. The risk of cancer development associated with alterations in these genes is lower, and there is a considerable population variability in different regions worldwide. AIM: We have performed mutation analyses of moderate-risk cancer susceptibility genes to evaluate their clinical importance for genetic counseling in high-risk patients suffering from breast and other cancers in the Czech population. RESULTS: Czech oncological patients were analysed for mutation in ATM, CHEK2, NBS1 (NBN) and PALB2 genes. The majority of analyzed individuals represent the population of high-risk BRCA1/2-negative BC patients. CONCLUSIONS: Based on results of this study, we recommend an analysis of recurrent truncating mutations in the CHEK2 gene (the c.1100delC mutation and a large deletion affecting exons 9-10) in BRCA1/2-negative patients from high-risk BC families. A clinical assessment of missense variants in CHEK2 is not suitable. A routine mutation analysis of the ATM and NBS1 (NBN) genes is not recommended in BC patients due to the low frequency of alterations in these genes in the Czech Republic. An identification of truncating mutations in the PALB2 gene is important in BRCA1/2-negative BC patients from families with a strong history of BC (HBC families). The frequency of PALB2 mutations may be comparable to the frequency of mutations in the BRCA2 gene in Czech HBC families.

[Diagnostics of breast cancer in high-risk women - our own experience]. / Diagnostika nádoru prsu ve skupine rizikových zen - vlastní zkusenosti.

Preventive oncology clinic of MMCI provides complex preventive care for women with high hereditary risk of breast and ovarian cancer due to germline mutations in BRCA1 and BRCA2 genes. Clinical follow-up is also provided to women with mutations in other genes causing a higher risk of different tumors, and also to women with increased lifetime empirical risk of breast cancer due to positive family history. Our clinic was established in 2000 and takes care for about 700 women. The goal of the clinic is to extend the life expectancy of these women to the level of the regular population. The risk of breast cancer can be reduced by prophylactic surgeries. Prophylactic mastectomy and oophorectomy are offered to women at a high risk. Other modality in breast cancer risk reduction is a chemoprevention by Tamoxifen. Most women accept only secondary prevention with the goal of the detection of breast cancer in clinical stage I, where the tumor is smaller than 1 cm and the risk of recurrence is less than 10%. The algorithm of prevention care was changed over the time and our diagnostic methods were improved by magnetic resonance imaging of breasts. During the 11 years of clinical follow-up 32 breast cancers in 31 women were detected. High risk women are examined every 6 month by physical examination, breast ultrasound and MRI plus mammography yearly.

The chromosome 2p21 region harbors a complex genetic architecture for association with risk for renal cell carcinoma.

In follow-up of a recent genome-wide association study (GWAS) that identified a locus in chromosome 2p21 associated with risk for renal cell carcinoma (RCC), we conducted a fine mapping analysis of a 120 kb region that includes EPAS1. We genotyped 59 tagged common single-nucleotide polymorphisms (SNPs) in 2278 RCC and 3719 controls of European background and observed a novel signal for rs9679290 [P = 5.75 × 10(-8), per-allele odds ratio (OR) = 1.27, 95% confidence interval (CI): 1.17-1.39]. Imputation of common SNPs surrounding rs9679290 using HapMap 3 and 1000 Genomes data yielded two additional signals, rs4953346 (P = 4.09 × 10(-14)) and rs12617313 (P = 7.48 × 10(-12)), both highly correlated with rs9679290 (r(2) > 0.95), but interestingly not correlated with the two SNPs reported in the GWAS: rs11894252 and rs7579899 (r(2) < 0.1 with rs9679290). Genotype analysis of rs12617313 confirmed an association with RCC risk (P = 1.72 × 10(-9), per-allele OR = 1.28, 95% CI: 1.18-1.39) In conclusion, we report that chromosome 2p21 harbors a complex genetic architecture for common RCC risk variants.

Genomic copy number alterations in clear cell renal carcinoma: associations with case characteristics and mechanisms of VHL gene inactivation.

Array comparative genomic hybridization was used to identify copy number alterations in clear cell renal cell carcinoma (ccRCC) patient tumors to identify associations with patient/clinical characteristics. Of 763 ccRCC patients, 412 (54%) provided frozen biopsies. Clones were analyzed for significant copy number differences, adjusting for multiple comparisons and covariates in multivariate analyses. Frequent alterations included losses on: 3p (92.2%), 14q (46.8%), 8p (38.1%), 4q (35.4%), 9p (32.3%), 9q (31.8%), 6q (30.8%), 3q (29.4%), 10q (25.7%), 13q (24.5%), 1p (23.5%) and gains on 5q (60.2%), 7q (39.6%), 7p (30.6%), 5p (26.5%), 20q (25.5%), 12q (24.8%), 12p (22.8%). Stage and grade were associated with 1p, 9p, 9q, 13q and 14q loss and 12q gain. Males had more alterations compared with females, independent of stage and grade. Significant differences in the number/types of alterations were observed by family cancer history, age at diagnosis and smoking status. Von Hippel-Lindau (VHL) gene inactivation was associated with 3p loss (P

Occupational exposure to dusts and risk of renal cell carcinoma.

BACKGROUND: Occupational exposures to dusts have generally been examined in relation to cancers of the respiratory system and have rarely been examined in relation to other cancers, such as renal cell carcinoma (RCC). Although previous epidemiological studies, though few, have shown certain dusts, such as asbestos, to increase renal cancer risk, the potential for other occupational dust exposures to cause kidney damage and/or cancer may exist. We investigated whether asbestos, as well as 20 other occupational dust exposures, were associated with RCC risk in a large European, multi-center, hospital-based renal case-control study. METHODS: General occupational histories and job-specific questionnaires were reviewed by occupational hygienists for subject-specific information. Odds ratios (ORs) and 95% confidence intervals (95% CIs) between RCC risk and exposures were calculated using unconditional logistic regression. RESULTS: Among participants ever exposed to dusts, significant associations were observed for glass fibres (OR: 2.1; 95% CI: 1.1-3.9), mineral wool fibres (OR: 2.5; 95% CI: 1.2-5.1), and brick dust (OR: 1.5; 95% CI: 1.0-2.4). Significant trends were also observed with exposure duration and cumulative exposure. No association between RCC risk and asbestos exposure was observed. CONCLUSION: Results suggest that increased RCC risk may be associated with occupational exposure to specific types of dusts. Additional studies are needed to replicate and extend findings.

TP53, EGFR, and KRAS mutations in relation to VHL inactivation and lifestyle risk factors in renal-cell carcinoma from central and eastern Europe.

Renal-cell carcinomas (RCC) are frequent in central and eastern Europe and the reasons remain unclear. Molecular mechanisms, except for VHL, have not been much investigated. We analysed 361 RCCs (334 clear-cell carcinomas) from a multi-centre case-control study for mutations in TP53 (exons 5-9 in the whole series and exons 4 and 10 in a pilot subset of 60 tumours) and a pilot 50 tumours for mutations in EGFR (exons 18-21) or KRAS (codon 12) in relation to VHL status. TP53 mutations were detected in 4% of clear-cell cases, independently of VHL mutations. In non-clear-cell carcinomas, they were detected in 11% of VHL-wild-type tumours and in 0% of tumours with VHL functional mutations. No mutations were found in EGFR or KRAS. We conclude that mutations in TP53, KRAS, or EGFR are not major contributors to the RCC development even in the absence of VHL inactivation. The prevalence of TP53 mutations in relation to VHL status may differ between clear-cell and other renal carcinomas.

Vitamin d pathway genes, diet, and risk of renal cell carcinoma.

Mediated by binding to the high-affinity vitamin D receptor (VDR), vitamin D forms a heterodimer complex with the retinoid-X-receptor (RXR). Variation in both genes has been shown to modify renal cell carcinoma (RCC) risk. Therefore, we investigated whether VDR and RXRA polymorphisms modify associations between RCC risk and frequency of dietary intake of vitamin D and calcium rich foods, and occupational ultraviolet exposure among 777 RCC case and 1035 controls from Central and Eastern Europe. A positive association was observed in this population between increasing dietary intake frequency of yogurt, while an inverse association was observed with egg intake frequency. RXRA polymorphisms, located 3' of the coding sequence, modified associations between specific vitamin D rich foods and RCC risk, while RXRA polymorphisms, located in introns 1 and 4, modified associations with specific calcium rich foods. Results suggest that variants in the RXRA gene modified the associations observed between RCC risk and calcium and vitamin D intake.

Genetic testing and prevention of hereditary cancer at the MMCI--over 10 years of experience.

Hereditary cancer syndromes are frequently seen in young cancer patients and patients with a positive family history. Genetic testing is important for the identification of high-risk individuals, and for the early introduction of specialized preventive care or prophylactic surgeries. High-risk tumour suppressor genes (BRCA1 and BRCA2) and DNA repair genes (MLH1, MSH2 and MSH6) are responsible for a substantial part of hereditary breast, ovarian and colorectal cancer. Other hereditary cancers are seen less frequently, but genetic testing has increased for many other site-specific cancers and complex syndromes. Genetic centres and molecular genetic laboratories are located mostly within university or regional hospitals. Some genetic centres are private. It is highly recommended (Czech Society for Medical Genetics) that all laboratories are accredited according to ISO 15,189 and that genetic testing of hereditary cancer syndromes is indicated by medical geneticists. The indication criteria and prevention strategies were published in Supplement 22 of Clinical Oncology 2009 (in Czech). Preventive care for high-risk individuals is organized by thirteen Oncology Centres, which provide most of the oncology care in the Czech Republic. Genetic testing and preventive care for high-risk individuals and mutation carriers is covered by health insurance. The molecular genetic laboratory at the MMCI provides molecular genetic testing of BRCA1, BRCA2, CHEK2 for hereditary breast/ovarian cancer, MLH1, MSH2, MSH6 for Lynch syndrome,TP53 for Li-Fraumeni syndrome, CDKN2A for familial malignant melanoma syndrome and CDH1 gene for hereditary diffuse gastric cancer. Other syndromes are tested in specialized laboratories elsewhere.The use of genetic testing is increasing because of more frequent referrals from oncologists and other specialists and the increasing variety of genes tested. However, in some patients the testing is not recommended and other family members are dying because of the late diagnosis of hereditary syndrome. Greater awareness of the importance of genetic testing in oncology is needed.

[Limitations of genetic testing in oncology]. / Limitace genetického testování v onkologii.

Genetic testing of cancer syndromes is based on the existing knowledge of monogenic causes of oncologic diseases. In cases of high-risk genes, the findings concerning the carrier status of pathogenic mutation can be of clinical use in the prediction of risks and for preventive care. In non-carriers in families with mutation in the high-risk gene, the risk of cancer diseases may not be the same as the population risk and some preventive follow-up is recommended. The clinical use of genes with mild or moderate risk of cancer is problematic and could lead to distorted conclusions about the actual cause of the familial form of the disease. Predictive testing in genes with moderate risk of cancer (2-3 times) is not offered, or the non-carriers are followed in the same way as carriers. The use of genes with mild risk is not recommended in clinical practice. Molecular genetic testing also has its limitations and its quality depends on the methods and technology used and the existing knowledge of the significance of mutations. In some variants it is not clear yet whether they are just insignificant polymorphisms or pathogenic mutations. The interpretation of test results in the context of the whole family history is important.

Vitamin D receptor polymorphisms and renal cancer risk in Central and Eastern Europe.

Previous studies investigated the role of vitamin D intake and cancer risk. The kidney is a major organ for vitamin D metabolism, activity, and calcium homeostasis; therefore, it was hypothesized that dietary vitamin D intake and polymorphisms in the vitamin D receptor (VDR) gene may modify renal cell carcinoma (RCC) risk. Three common VDR gene polymorphisms (BsmI, FokI, TaqI) were evaluated among 925 RCC cases and 1192 controls enrolled in a hospital-based case-control study conducted in Central and Eastern Europe. Overall associations with RCC risk were not observed; however, subgroup analyses revealed associations after stratification by median age of diagnosis and family history of cancer. Among subjects over 60 yr, reduced risks were observed among carriers of the f alleles in the FokI single-nucleotide polymorphism (SNP) (odds ratio [OR] = 0.61 for Ff and OR = 0.74 for ff genotypes) compared to subjects with the FF genotype (P trend = 0.04; P interaction = 0.004). Subjects with the BB BsmI genotype and a positive family history of cancer had lower risk compared to subjects with the bb allele (OR = 0.60; 95% CI: 0.33-1.1; P trend = 0.05). Genotype associations with these subgroups were not modified when dietary sources of vitamin D or calcium were considered. Additional studies of genetic variation in the VDR gene are warranted.

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.