MED12 exon 2 mutation as a highly sensitive and specific marker in distinguishing phyllodes tumours from other spindle neoplasms of the breast

Spindle neoplasms of the breast (SNB) primarily include metaplastic breast carcinoma (MBC), phyllodes tumour (PT), fibromatosis and primary nonspecific sarcoma (PNS). Mutations in MED12 exon 2 have been reported in PTs. Because spindle tumour components are shared by SNB, we assessed the diagnostic use of MED12 exon 2 mutation in SNB. We investigated MED12 exon 2 mutations in a total of 91 samples of SNB, including 49 PT cases that have been previously analysed. Mutations were identified using direct sequencing. MED12 exon 2 mutation was absent in all cases of MBC, fibromatosis and PNS, in contrast to the 71.4% positivity in PTs. MED12 mutations were identified in four of six previously diagnosed monophasic sarcomatous MCB cases, however, these four cases were revised as malignant PT based on additional bcl‐2 staining, albeit very focal. Consistence in the MED12 mutational status between a paired core biopsy and a surgical specimen was observed in all 20 tested PT cases. In conclusion, we demonstrated the restriction of MED12 exon 2 mutation to PTs (73.6%, 39/53) and its absence in other SNB. MED12 exon 2 mutational analysis can be included in the differential diagnosis between PT and other SNB, especially with limited specimen where diagnostic clues are not evident.     

Regional biases in mutation screening due to intratumoural heterogeneity of prostate cancer

Intratumoural heterogeneity (ITH) leads to regional biases of the mutational landscape in a single tumour and may influence the single biopsy‐based clinical diagnosis and treatment decision. To evaluate the extent of ITH in unifocal prostate cancers (PCAs), we analysed multiple regional biopsies from three PCAs, using whole‐exome sequencing, DNA copy number and gene expression profiling analyses. A substantial level of ITH was identified, in that 0–61% and 18–71% of somatic variants were common or private, respectively, within a given cancer. The enhanced mutation detection rate in the combined sequencing dataset across intratumoural biopsies was demonstrated with respect to the total number of mutations identified in a given tumour. Allele frequencies of the mutations were positively correlated with the levels of intratumoural recurrence (private < shared < common), but some common mutations showed low allele frequency, suggesting that not all were clonally fixed. Regional biases in the presentation of a well‐known TMPRSS2–ERG fusion was noted in one PCA and the somatic mutation‐ and copy number‐based phylogenetic relationships between intratumoural biopsies were largely concordant. Genes showing intratumoural expression variability were commonly enriched in the molecular function of eicosanoid metabolism and PCA‐relevant clinical markers. Taken together, our analyses identified a substantial level of genetic ITH in unifocal PCAs at the mutation, copy number and expression levels, which should be taken into account for the identification of biomarkers in the clinical setting. Copyright © 2014 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.     

结直肠癌患者循环肿瘤DNA定量KRAS基因突变的检测

目的建立结直肠癌KRAS基因G12D液体活检技术,并探讨其在结直肠癌诊疗中的应用价值。方法用微滴式数字PCR(ddPCR)技术定量检测52例结直肠癌患者和80名健康对照的血浆游离DNA的KRAS基因G12D突变率和突变浓度;以结直肠癌患者肿瘤组织KRAS基因测序结果为金标准评价ddPCR检测的准确性;分析结直肠癌患者KRAS基因G12D突变率、浓度与其临床表征的关系。结果结直肠癌患者血浆KRAS基因G12D突变型检出率(26.92%)和浓度中位数(81.5 copies/m L)显著高于健康对照(8.75%,16 copies/m L);结直肠患者组高分化腺癌的KRAS基因G12D突变浓度显著高于中分化和低分化腺癌(P<0.05),淋巴结转移N2的KRAS基因G12D突变浓度显著高于N0和N1(P<0.05);结直肠癌患者血浆KRAS基因G12D突变与肿瘤组织突变一致性达87.50%。结论ddPCR检测方法是一种快速、无创和准确的检测血浆循环肿瘤DNA(ctDNA)的方法,其检测结果可为临床用药指导和病程监控提供依据。     

Behavior of 10 patients with FG syndrome (Opitz-Kaveggia syndrome) and the p.R961W mutation in the MED12 gene

Opitz and Kaveggia [Opitz and Kaveggia (1974); Z Kinderheilk 117:1-18] reported on a family of five affected males with distinctive facial appearance, mental retardation, macrocephaly, imperforate anus and hypotonia. Risheg et al. [Risheg et al. (2007); Nat Genet 39:451-453] identified an identical mutation (p.R961W) in MED12 in six families with Opitz-Kaveggia syndrome, including a surviving affected man from the family reported in 1974. The previously defined behavior phenotype of hyperactivity, affability, and excessive talkativeness is very frequent in young boys with this mutation, along with socially oriented, attention-seeking behaviors. We present case studies of two older males with FG syndrome and the p.R961W mutation to illustrate how their behavior changes with age. We also characterize the behavior of eight additional individuals with FG syndrome and this recurrent mutation in MED12 using the Vineland Adaptive Behavior Scales 2nd edition, the Reiss Profile of Fundamental Goals and Motivation Sensitivities, and the Achenbach Child Behavior Checklist. Males with this MED12 mutation had deficits in communication skills compared to their socialization and daily living skills. In addition, they were at increased risk for maladaptive behavior, with a propensity towards aggression, anxiety, and inattention. Based on the behavior phenotype in 10 males with this recurrent MED12 mutation, we offer specific recommendations and interventional strategies. Our findings reinforce the importance of testing for the p.R961W MED12 mutation in males who are suspected of having developmental and behavioral problems with a clinical phenotype that is consistent with FG syndrome.     

新疆地区维吾尔族乳腺癌BRCA1基因突变分析

目的研究新疆地区维吾尔族乳腺癌患者BRCA1基因突变情况及突变位置。方法选取70例维吾尔族乳腺癌根治标本,对照组为32例维汉族乳腺良性病变（纤维腺病及纤维腺瘤）及乳腺癌旁非癌组织;应用PCR-单链构象多态性和DNA序列测定的方法检测BRCA1基因突变。结果（1）70例维吾尔族乳腺癌中发现9例BRCA1突变的12个新位点。（2）70例维吾尔族乳腺癌BRCA1的突变率为12.86%（9/70）,22例维吾尔族早发性乳腺癌（≤35岁）BRCA1突变率为31.82%（7/22）。维吾尔族早发性乳腺癌BRCA1突变率（7/22）高于维吾尔族晚发性乳腺癌（2/48）,差异有统计学意义（χ^2=10.295,P〈0.01）。（3）70例维吾尔族乳腺癌中发现9例BRCA1基因核苷酸多态性位点,其中8例多态性位点均为3232A〉G。（4）2例双侧乳腺癌中均检测出BRCA1基因的突变。结论BRCA1突变可能与新疆维吾尔族乳腺癌尤其是维吾尔族早发性乳腺癌及双侧乳腺癌的发生密切相关。     

Negative 34betaE12 staining in a small focus of atypical glands on prostate needle biopsy: a follow-up study of 332 cases

Atypical glands on prostate needle biopsy with a negative 34betaE12 (cytokeratin 903; CK903) immunostain, indicating a lack of a basal cell layer, are typically diagnostic of prostate cancer. However, in certain cases a negative 34betaE12 immunostain in a small focus of atypical glands is still not convincing enough to make the diagnosis of cancer. This study is the first report to evaluate the incidence of prostate cancer on follow-up biopsy in individuals with this diagnosis. A total of 543 men who had prostate core biopsy specimens diagnosed as a small focus of atypical-appearing glands with a negative 34betaE12 immunostain between January 1, 1997 and December 31, 2000 were selected for study. Some 61% of these 543 individuals (n = 332) had undergone at least one follow-up biopsy procedure. Of these, 43% of repeat biopsy cases (n = 142) were diagnostic of prostate cancer. A total of 46 individuals had at least 2 follow-up biopsy procedures, with 48% of these (n = 22) being diagnosed as cancer. The Gleason grades of the detected carcinomas were broken down as follows: Gleason grade 3 + 2 = 5, 6%; grade 3 + 3 = 6, 86%; grade 3 + 4 = 7, 1%; grade 4 + 3 = 7, 4%; and grade 4 + 4 = 8, 3%. The median amount of time to the first follow-up biopsy was 79 days, with 52% of follow-up biopsies performed within 90 days. A negative 34betaE12 immunohistochemical stain in a small focus of atypical glands is not associated with an increased prediction of prostate cancer on follow-up biopsy (43%), compared with previously published data for "small focus of atypical glands" alone (approximately 45%). Because 48% of men with an initial negative biopsy and multiple follow-up biopsy procedures were found to have cancer, more than one repeat biopsy session or more extensive sampling on the first repeat biopsy procedure may be necessary to maximize the identification of cancer. This finding is similar to that found in men with atypical diagnoses in general, without a negative 34betaE12 immunohistochemical stain. Only half of all individuals with a diagnosis of 34betaE12-negative focus of atypical glands underwent repeat biopsy within 3 months. Urologists need to be educated as to the significance of an atypical diagnosis and the need for repeat biopsy. In a small focus of atypical glands on prostate biopsy, negative staining for 34betaE12 should not necessarily lead to a definitive malignant diagnosis in all cases, because almost half of these biopsies on follow-up sampling are benign.     

High molecular weight cytokeratin antibody (clone 34betaE12): a sensitive marker for differentiation of high-grade invasive urothelial carcinoma from prostate cancer

AIMS: There is no well-established positive immunomarker for urothelial carcinoma. We evaluated the diagnostic utility of high molecular weight cytokeratin (HMWCK) antibody clone 34betaE12 in differentiating high-grade invasive urothelial carcinoma from prostate cancer. METHODS AND RESULTS: Formalin-fixed paraffin-embedded sections from 28 cases of high-grade invasive urothelial carcinoma (20 not otherwise specified (UC-NOS), eight with glandular differentiation) and 20 cases of poorly differentiated prostate carcinoma were immunostained with a monoclonal antibody to carcinoembryonic antigen (CEA), clone 85A12 and with HMWCK antibody clone 34betaE12 after microwave pretreatment or protease 24 predigestion. All cases of UC-NOS expressed HMWCK on 34betaE12 immunostaining after microwaving or enzyme predigestion. Immunoreactivity was intense and diffuse in all the cases after microwave pretreatment, whilst with enzyme predigestion immunoreactivity was sometimes patchy with <50% tumour cells positive in 20% of cases. In comparison with 34betaE12, 85A12 was insensitive with 15% of UC-NOS cases totally CEA-negative and <50% tumour cell immunoreactivity in 60% of cases. Rare positive cells were present in two (10%) cases of prostate cancer with monoclonal anti-CEA and 34betaE12 on microwaved sections, but all the cases were HMWCK-negative using 34betaE12 on sections pretreated by enzyme digestion. CONCLUSIONS: HMWCK antibody clone 34betaE12, particularly when used with microwave heat retrieval, is a very sensitive positive marker for high-grade invasive urothelial carcinoma.     

Severe Mycobacterium bovis BCG infections in a large series of novel IL-12 receptor beta1 deficient patients and evidence for the existence of partial IL-12 receptor beta1 deficiency

Cell mediated immunity plays a critical role in human host defence against intracellular bacteria. In patients with unusual, severe infections caused by poorly pathogenic species of mycobacteria and salmonellae, genetic deficiencies have been identified in key genes in the type-1 cytokine pathway, especially in IFNGR1 and IL12RB1. Here, we analyzed 11 patients originating from Turkey and suffering from unusual Mycobacterium bovis Bacille Calmette-Guerin infections following vaccination, and found that most patients (n=8) are deficient in IL-12Rbeta1 expression and function. No defects were found in patients' IFN-gammaR or IL-18R. In addition, a first patient suffering from partial IL-12Rbeta1 deficiency is described. This patient presented with an intermediate cellular and immunological phenotype: a consistent, low response to IL-12 was found, which could be further augmented by IL-18. Despite a lack of cell surface IL-12Rbeta1 expression, normal levels of intracellular IL-12Rbeta1 protein were detectable, which was not seen in the other, completely IL-12Rbeta1 deficient patients examined. Moreover, this patient had a relatively mild clinical phenotype and was the only individual with a single homozygous amino acid substitution in IL-12Rbeta1 (C198R). Collectively, our findings indicate that idiopathic, unusually severe infections due to M. bovis BCG can be caused by complete as well as partial IL-12Rbeta1 deficiency.     

p.L18P: a novel IDUA mutation that causes a distinct attenuated phenotype in mucopolysaccharidosis type I patients

Mucopolysaccharidosis type I is a rare autosomal recessive disorder caused by deficiency of α‐l ‐iduronidase (IDUA) which leads to a wide spectrum of clinical severity. Here, we describe the case of four male patients who present the previously undescribed p.L18P mutation. Patient 1 (p.L18P/p.L18P) presents, despite multiple joint contractures, an attenuated phenotype. Patient 2 (p.L18P/p.W402X) was diagnosed at 4 years of age with bone dysplasia, coarse facies, limited mobility, claw hands and underwent bilateral carpal tunnel surgery at 6 years of age. Patients 3 and 4 (both p.L18P/p.L18P) are brothers. Patient 3 was diagnosed at 4 years of age, when presented claw hands, lower limb and shoulder pain, restricted articular movement and bilateral carpal tunnel syndrome. Patient 4 was diagnosed at 17 months of age when presented lower limb pain at night, respiratory allergy and repeated upper airways infections. Bioinformatics analysis indicates that p.L18P mutation reduces the signal peptide to 25 amino acids and alters its secondary structure. In conclusion, we report a new IDUA variant that alters the structure of the signal peptide, which likely impairs transport to lysosomes. Moreover, it leads to a distinct attenuated phenotype with mainly bone and cartilage symptoms, without visceromegalies, heart disease, or cognitive impairment.     

Needle core biopsies provide ample material for genomic and proteomic studies of kidney cancer: observations on DNA, RNA, protein extractions and VHL mutation detection

The use of needle biopsies in basic research is increasing, and our study provides a comprehensive analysis of their adequacy in genomic and proteomic studies of kidney cancer. Frozen clear cell renal cell carcinoma (ccRCC) needle core biopsies and sections from core biopsies embedded in optimal cutting temperature (OCT) compound were used to extract DNA, RNA and protein. Their integrity was determined using genomic and proteomic analyses. VHL mutation testing was performed on ccRCC biopsies and corresponding tumors using bulk and laser capture microdissection (LCM) extractions for comparison. Adequate amounts of good quality DNA (5.8-13.3 μg/whole core, 0.6-2.7 μg/20 sections), RNA (2.9-11.9 μg/whole core, 0.5-1.3 μg/20 sections) and protein (137.4-444 μg/whole core, 39.9-74.1 μg/20 sections) were obtained from whole core and frozen sections of ccRCC needle biopsies, respectively. We observed VHL sequence mutations in 75% of ccRCC tumors and, in most cases, the same mutations were detected in both tumors and corresponding biopsies. Mutations observed by bulk extractions from tumors and biopsies were also detected by LCM without significant differences between both methodologies. ccRCC needle biopsies provide ample material for genomic and proteomic studies of kidney cancer. They are good representatives of their corresponding tumors for VHL mutation detection using both bulk and LCM extractions. LCM does not increase sensitivity of VHL mutation detection.     

Nickel accumulation in lung tissues is associated with increased risk of p53 mutation in lung cancer patients

Occupational exposure to nickel compounds has been associated with lung cancer. The correlation between high nickel levels and increased risk of lung cancer has been previously reported in a case–control study. This study assessed whether nickel exposure increased the occurrence of p53 mutations due to DNA repair inhibition by nickel. A total of 189 lung cancer patients were enrolled to determine nickel levels in tumor‐adjacent normal lung tissues and p53 mutation status in lung tumors through atomic absorption spectrometry and direct sequencing, respectively. Nickel levels in p53 mutant patients were significantly higher than those in p53 wild‐type patients. When patients were divided into high‐ and low‐nickel subgroups by median nickel level, the high‐nickel subgroup of patients had an odds ratio (OR) of 3.25 for p53 mutation risk relative to the low‐nickel subgroup patients. The OR for p53 mutation risk of lifetime non‐smokers, particularly females, in the high‐nickel subgroup was greater than that in the low‐nickel subgroup. To determine whether nickel affected DNA repair capacity, we conducted the host cell reactivation assay in A549 and H1975 lung cancer cells and showed that the DNA repair activity was reduced by nickel chloride in a dose‐dependent manner. This was associated with elevated production of hydrogen peroxide‐induced 8‐oxo‐deoxyguanosine. Therefore, increased risk of p53 mutation due to defective DNA repair caused by high nickel levels in lung tissues may be one mechanism by which nickel exposure contributes to lung cancer development, especially in lifetime female non‐smokers. Environ. Mol. Mutagen. 55:624–632, 2014. © 2014 Wiley Periodicals, Inc.     

Mutations predisposing to breast cancer in 12 candidate genes in breast cancer patients from Poland

A number of genes other than BRCA1 and BRCA2 have been associated with breast cancer predisposition, and extended genetic testing panels have been proposed. It is of interest to establish the full spectrum of deleterious mutations in women with familial breast cancer.We performed whole‐exome sequencing of 144 women with familial breast cancer and negative for 11 Polish founder mutations in BRCA1, CHEK2 and NBS1, and we evaluated the sequences of 12 known breast cancer susceptibility genes. A truncating mutation in a breast cancer gene was detected in 24 of 144 women (17%) with familial breast cancer. A BRCA2 mutation was detected in 12 cases, a (non‐founder) BRCA1 mutation was detected in 5 cases, a PALB2 mutation was detected in 4 cases and an ATM mutation was detected in 2 cases. Polish women with familial breast cancer who are negative for founder mutations in BRCA1, CHEK2 and NBS1 should be fully screened for mutations in BRCA1, BRCA2 and PALB2. The PALB2 founder mutation c.509_519delGA should be included in the panel of Polish founder mutations.