DNA methylation at an enhancer of the three prime repair exonuclease 2 gene (TREX2) is linked to gene expression and survival in laryngeal cancer

Background

Genetic aberrations in DNA repair genes are linked to cancer, but less is reported about epigenetic regulation of DNA repair and functional consequences. We investigated the intragenic methylation loss at the three prime repair exonuclease 2 (TREX2) locus in laryngeal (n = 256) and colorectal cancer cases (n = 95) and in pan-cancer data from The Cancer Genome Atlas (TCGA).

Results

Significant methylation loss at an intragenic site of TREX2 was a frequent trait in both patient cohorts (p = 0.016 and < 0.001, respectively) and in 15 out of 22 TCGA studies. Methylation loss correlated with immunohistochemically staining for TREX2 (p < 0.0001) in laryngeal tumors and improved overall survival of laryngeal cancer patients (p = 0.045). Chromatin immunoprecipitation, demethylation experiments, and reporter gene assays revealed that the region of methylation loss can function as a CCAAT/enhancer binding protein alpha (CEBPA)-responsive enhancer element regulating TREX2 expression.

Conclusions

The data highlight a regulatory role of TREX2 DNA methylation for gene expression which might affect incidence and survival of laryngeal cancer. Altered TREX2 protein levels in tumors may affect drug-induced DNA damage repair and provide new tailored therapies.

Electronic supplementary material

The online version of this article (10.1186/s13148-019-0666-5) contains supplementary material, which is available to authorized users.

Abstract 3364: DNA methylation loss at an enhancer site of the DNA repair gene TREX2 is an epigenetic feature in multiple cancers

The onset of numerous cancers is strongly associated with exposure to genotoxic agents and is counteracted by cellular DNA repair mechanisms. However, the tumorigenic potential of genotoxic carcinogens varies widely among individuals. It is still uncertain which genetic and epigenetic traits shape cancer onset and progression in the general population. While genetic aberrations in DNA repair genes have been linked to cancer risk, less is known about the importance of epigenetics for the regulation of these genes. In order to identify DNA methylation alterations in laryngeal cancer we carried out targeted DNA methylation analysis at single CpG sites via mass spectrometry. We focused our analysis on five DNA repair-associated gene loci previously found to be altered in head and neck squamous cell carcinoma. We report loss of DNA methylation at the three prime repair exonuclease 2 (TREX2) gene locus in laryngeal cancer (n=161) and adjacent normal tissue (n=58) samples of patients from a German population-based case-control study. Following screening of tumor tissues from Chinese colorectal cancer patients as well as previously published data from the Cancer Genome Atlas (TCGA), we identified TREX2 methylation loss as a frequent trait in multiple cancers. We further characterized the regulatory activity of the affected TREX2 site using chromatin immunoprecipitation and luciferase reporter assays in cell models from different tumor types. Differential TREX2 methylation affects a CCAAT/enhancer binding protein alpha (CEBPA) binding site serving as a gene enhancer which drives the expression of TREX2 from a previously uncharacterized gene promoter. We also observed a strong association between TREX2 methylation and TREX2 protein expression determined via immunohistochemistry in laryngeal tumors. Finally, we found a significant association between overall survival and loss of TREX2 methylation in laryngeal cancer, with TREX2 methylation loss being a protective factor. Our findings highlight a profound regulatory role of epigenetic mechanisms for TREX2 in tumors, and underline the usefulness of TREX2 DNA methylation as a biomarker for patient stratification.

Citation Format: Christoph Weigel, Jittiporn Chaisaingmongkol, Christine Kuhmann, Irene Santi, Volker Winkler, Olga Bogatyrova, Justo L. Bermejo, Tsun L. Chan, Felix Lasitschka, Manfred H. Bohrer, Alexander Marx, Frank Autschbach, Roland Heyni-von Haußen, Gerhard Dyckhoff, Klaus-Wolfgang Delank, Karl Hoermann, Burkard M. Lippert, Gerald Baier, Andreas Dietz, Christopher C. Oakes, Christoph Plass, Heiko Becher, Peter Schmezer, Heribert Ramroth, Odilia Popanda. DNA methylation loss at an enhancer site of the DNA repair gene TREX2 is an epigenetic feature in multiple cancers [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3364. doi:10.1158/1538-7445.AM2017-3364

Fibroelastoma Recurrence in Left Ventricle: Rarity of Primary Cardiac Tumor

Cardiac papillary fibroelastoma (CPF) is a primary cardiac neoplasm usually detected by echocardiography. Left ventricular fibroelastomas are extremely rare. The incidence of CPF is between 0.0017 and 0.33% during autopsy studies. We report a 70-year-old man who had papillary fibroelastoma discovered and resected in 2005 that recurred in 2013. The tumor grew rapidly from 2013 to 2014. A bioprosthetic mitral valve was placed in 2014. Due to the location and nature of the recurrent tumor, mitral valve replacement was the treatment of choice to prevent a third recurrence of the fibroelastoma. The patient was discharged from the hospital on postoperative day 9.

[30 year-old patient with multiple pelvic lesions and fecal incontinence]

In a 30 year-old patient with subacute loss of bowel control and perianal anesthesia radiologic examination showed multiple bone lesions. The results of a bone marrow aspiration showed acute myeloid leukemia M2 with translocation t(8,21) associated with granulocytic sarcoma. The patient was treated with high dose chemotherapy and had a complete remission after autologous stem cell transplantation.

Unklare hepatische Raumforderungen: Häufigkeit von Adenokarzinom-Metastasen eines unbekannten Primärtumors

BACKGROUND AND OBJECTIVE

The diagnostic approach to newly detected space-occupying lesions in the liver can be difficult and a histogenetic classification of the primary tumor is impossible in some cases. Such cases of metastatic disease without a detectable primary tumor are classified as cancer of unknown primary site (CUP). The incidence of this diagnosis depends on the clinical and histochemical methods used. It was the main aim of this study to analyze the true incidence of adenocarcinoma metastases of the liver with an unknown primary cancer after application of a standardized protocol of clinical and immunhistochemical diagnostic tests and a long-term follow-up.

PATIENTS AND METHODS

Between January 2000 and January 2003 127 consecutive patients underwent diagnostic ultrasound-guided biopsy of a space-occupying lesion in the liver. Based on the histopathology and immunochemistry a well defined and individually adapted diagnostic algorithm was employed (endoscopy, imaging).

RESULTS

44 females and 83 males, median age 66.8 years, were enrolled into the study. Primary tumors of the liver were found in 21 cases and non-hepatocellular tumors (metastases) were documented in 106 patients, 82 of the latter (77%) had metastases of an adenocarcinoma. The further diagnostic approach was based on histochemistry, immunhistochemistry and imaging techniques, making possible a full diagnosis of primary tumor in a further 59 (72%) cases. Thus the incidence of an adenocarcinoma of the liver of unknown primary site was 23 of 127 cases (18%).

CONCLUSIONS

Although there is a wide variety of modern diagnostic methods today, the histogenetic classification of hepatic metastases is not always possible. However, in the last few years diagnostic advances have occurred based on modern immunhistochemical methods. This immunhistochemical definition has made it possible to avoid an oppressive "overdiagnosis" and offer patients early and appropriate therapeutic options.

Accuracy of high-resolution chromoendoscopy in prediction of histologic findings in diminutive lesions of the rectosigmoid

BACKGROUND

The ability to differentiate adenomatous from nonadenomatous colonic polyps by using chromoendoscopy would obviate the need to remove hyperplastic lesions. The aim of this study was to define the accuracy of high-resolution chromoendoscopy for the determination of colonic polyp histology.

METHODS

In 158 patients, 273 polyps (<5 mm) in the rectosigmoid were estimated for their histology. The endoscopists, in two steps, predicted the histopathology of each lesion on the basis of its surface characteristics by using high-resolution colonoscope without any staining and after indigo carmine dye according to the Kudo classification.

RESULTS

The resected polyps included 48 adenomatous and 225 nonadenomatous polyps. When histologically confirmed hyperplastic polyps were compared with adenomatous polyps, the prediction of hyperplastic polyps based on endoscopic findings had a sensitivity of 93%, a specificity of 60%, and an overall accuracy of 81%. The corresponding sensitivity, specificity, and overall accuracy after indigo carmine dye were 94%, 64%, and 83%, respectively.

CONCLUSIONS

The results suggest that the chromoendoscopy only marginally improves the determination between hyperplastic and adenomatous polyps when using high-resolution colonoscopes. The overall accuracy rate increased after dyeing, from 81% to 83%. The omission of histopathologic analysis cannot yet be achieved by chromoendoscopy.

[Space-occupying lesion of the pancreas--how frequently not due to a suspected ductal adenocarcinoma?]

In patients with a space-occupying lesion of the pancreas at first a primary ductal adenocarcinoma is considered as the cause. Other tumours or metastases are assumed to occur very rarely. Therapy and prognosis of other pancreas tumours differ from therapy and prognosis of a primary ductal adenocarcinoma. We therefore examined the question of how frequently a space-occupying lesion of the pancreas was not due to a ductal adenocarcinoma in our case materials. Retrospectively 70 patients who had undergone a percutaneous puncture of a space-occupying mass of the pancreas under ultrasonographic control were included in the study (34 women, 36 men). In 62 patients a clear histological diagnosis was possible on the basis of the biopsy. In 53 cases (76 %) a primary adenocarcinoma of the pancreas could be diagnosed. In 5 patients (7 %) these masses turned out to be metastases of a previously known malignant tumour disease (2 x mammary carcinoma, 2 x gastric carcinoma, 1 x sigmoid carcinoma). Other tumours could be detected in 4 cases (6 %) including a tuberculoma, an endocrine tumour, a fusocellular sarcoma with partial neurogenic differentiation and a large-cell and pleomorphic-cell anaplastic, partly sarcomatoid carcinoma. In patients with a space-occupying lesion of the pancreas, tumours other than a ductal adenocarcinoma are not rare. In particular, in cases of a previously known malignant tumour disease a space-occupying lesion of the pancreas can also turn out to be a metastasis. Every other individual tumour entity is rare. Other tumour entities at large, however, are found in daily routine. The preoperative biopsy of space-occupying lesions of the pancreas, therefore, still has a clinical importance for the further therapy planning.

Does Cytokeratin7/20 immunoreactivity help to distinguish Barrett's esophagus from gastric intestinal metaplasia? Results of a prospective study of 75 patients

Barrett's esophagus is a recognized risk factor for the development of esophageal dysplasia and carcinoma. Unfortunately, gastric incomplete intestinal metaplasia arising in Short Segment Barrett's esophagus can be indistinguishable histologically on hematoxylin/eosin stains. Distinct patterns of CK 7 and CK 20 immunohistochemical expression have been demonstrated to be both highly sensitive and specific for Barrett's esophagus, but have not been found in gastric metaplasia. The aim of our study was to test whether immunostaining with CK 7/20 helps to distinguish between Barrett's epithelium and gastric incomplete metaplasia. Cases of long segment Barrett's esophagus, short segment Barrett's esophagus, and cases with a normal gastroesophageal junction, as well as specimens with gastric antral intestninal metaplasia, were examined: three patterns were defined. Barrett's pattern (superficial CK 20 staining; superficial and crypt CK 7 staining); gastric pattern (superficial and crypt staining of both markers); other patterns (different from Barrett and gastric types). Seventy-five patients were enrolled in this study, 26 with long segment Barrett's esophagus, 21 with short segment esophagus, 13 with intestinal metaplasia of the cardia, and 18 with antral intestinal metaplasia. The Barrett pattern showed a high specificity of 97%, but a sensitivity of only 30% in patients with short segment Barrett esophagus. Our results do not confirm the hypothesis that CK 7/20 immunostaining can be used for a reliable differentiation between incomplete intestinal metaplasia and Barrett's epithelium.

Die Diagnose einer Leberzirrhose: Ein Vergleich der Wertigkeit von Standardlaparoskopie, Minilaparoskopie und Histologie

BACKGROUND

The superiority of laparoscopy with guided biopsy over biopsy alone is established. It is still uncertain if this is also true for midi-/ and mini-laparoscopy.

AIM

The aim of this study was to determine the diagnostic gain of laparoscopic-guided biopsy for standard laparoscopy and the use of midi-/mini-laparoscopies. Characteristics of the liver biopsies were investigated with regard to a missed diagnosis of cirrhosis.

METHODS

In a consecutive series of 425 patients clinical, laparoscopic and histological findings were investigated. The length and fragmentation of the liver biopsies were investigated with regard to a missed diagnosis of cirrhosis.

RESULTS

The sensitivity of laparoscopy in the diagnosis of cirrhosis was 96 %, that of histology 68 %. The sensitivity of histology alone was especially low in macronodular cirrhosis. The sensitivity of both laparoscopy and histology improved from Child A to C. When cirrhosis was apparent, liver biopsies were shorter and more frequently fragmented. However, the diagnosis of cirrhosis was independent of these parameters.

CONCLUSION

Mini-laparoscopy may replace standard laparoscopy and appears to be superior compared with histology alone.

[Heavy diarrhea by low malignant B cell lymphoma]

A 52-year old female presented with a low, malignant centroblastic-centrocytic lymphoma. After splenectomy and under steroid therapy it came to the eruption of a latent Strongyloides stercoralis infection, which the patient had presumably been suffering from for several years. Due to the immunodeficient condition and under continued steroid therapy even three courses of high dose anthelmintic therapy could not eradicate the parasites. The patient died of fulminant sepsis.

[Endometriosis of the transverse colon--a rare localization]

HISTORY

A 65-year-old woman with no complaints came to our hospital for a colonoscopy because of a family history of a colorectal carcinoma. Because of postmenopausal complaints she had been undergoing estrogen therapy for the past five years.

INVESTIGATIONS

Colonoscopy revealed a 2 x 2 cm polyp like structure with central tissue proliferation in the transverse colon. Neither chromoendoscopy with indigocarmine nor multiple biopsies indicated an adenomatous glandular proliferation. Miniendosonography revealed the image of a tumour located in the muscularis propria. DIAGNOSIS AND CLINICAL COURSE: As a malign process could not definitely be excluded, a colon segment resection was carried out by laparoscopy. In the operative specimen there was a 2 x 2 cm large tumour growing under the mucosa. Histologically it was an intramural manifestation of an extragenital endometriosis in the area of the muscularis propria with resulting nodular proliferation of the local muscle system. The ectopic endometrial glands in the area of the endometriosis revealed a complex hyperplasia without atypical features, an image suggesting oestrogen stimulation.

CONCLUSION

In many cases the diagnosis of an intestinal endometriosis can not be made through a non-invasive diagnostic method such as colonoscopy with biopsy because of the intramural localisation in the muscularis propria. In order to safely rule out a malignant lesion, in unclear cases a resection should be aimed at.

[The hyperplastic gastric polyp - a praecancerosis?]

In general, hyperplastic polyps of the stomach are regarded as benign lesions. Still there is the chance to find carcinomas within them as documented in this case report. This finding can be interpreted as an incidental appearance. At the moment there are no standardized guidelines regarding diagnostics and therapy of gastric hyperplastic polyps. Referring to a short review of the literature endoscopic snare polypectomy seems to be a reasonable therapeutic option of hyperplastic polyps with a size of 0.5-1 cm. Although it is possible to determine the histology by forceps biopsy, it is possible to be misled by missing areas of focal carcinomas. Complications after polypectomy are rare and often no further intervention is needed. A further point for polypectomy is the fact that surfaces of hyperplastic polyps are eroded in about 90 % and therefore there is the risk of bleeding, chronic anaemia and positive stool tests for occult blood.

Phenprocoumon-assoziierte nekrotisierende Hepatitis

CLINICAL PRESENTATION

A 52-year-old female patient presented at our hospital with right upper abdominal pain and impaired general condition. During the previous 7 months, the patient had received anticoagulation treatment with phenprocoumon due to a prosthetic aortic valve replacement.

TESTS

Serological tests for virologic, autoimmune or metabolic causes of hepatitis were negative. The histologic examination of liver biopsies showed necrotizing hepatocellular injury in zone 3 of the acinus without relevant fibrosis. Initially, a lymphocyte transformation test with phenprocoumon was negative. A second test after one week turned out to be positive. DIAGNOSIS AND CLINICAL COURSE: After withdrawal from phenprocoumon therapy and switching to anticoagulation with a low molecular weight heparin, liver tests gradually became normal. Aminotransferase levels rapidly increased when phenprocoumon treatment was resumed. Phenprocoumon-associated necrotizing hepatitis was diagnosed by clinical course, liver histology and the positive lymphocyte transformation test. After immunosuppressive treatment with prednisolone was started again, liver enzymes gradually normalized. Anticoagulation was further performed with low molecular weight heparin.

CONCLUSION

This case stresses the fact that an adequate and detailed history on concomitant medication is mandatory in patients who present with cryptic hepatitis. Though severe hepatic adverse effects of phenprocoumon are rare, physicians should consider coumarin derivatives as a potential source of hepatitis.

DNA-zytometrische Untersuchungen der Barrett-Mukosa

BACKGROUND

Barrett's esophagus predisposes to cancer development. The diagnosis of dysplastic precursor lesions is impaired by problems of subjectivity. In the present study, DNA ploidy results of patients with Barrett's esophagus were related to the grade of dysplasia and to the progress of the disease.

PATIENTS AND METHODS

In 61 patients with Barrett's esophagus, DNA ploidy was determined by image cytometry on imprints. All biopsies (n = 145) were histologically examined for dysplasia distinguishing between low- and high-grade dysplasia, and dysplasia-negative.

RESULTS

A significant correlation (p < 0.001) between DNA ploidy and the grade of dysplasia was found, with 81% euploid DNA results in biopsies negative for dysplasia and 86% abnormal DNA patterns in biopsies with high-grade dysplasia. The subgroup of low-grade dysplasia showed a heterogeneous DNA ploidy. It is important to note that nearly 20% of biopsies classified dysplasia-negative contained abnormal single cells or abnormal stemlines regarding DNA content. In several cases, suspect DNA results caused a modified reclassification of dysplasia, and there were cases in which patients negative for dysplasia but positive for abnormal DNA ploidy developed dysplasia later on.

CONCLUSION

In patients with Barrett's esophagus, DNA ploidy by image cytometry is a suitable additive method for histological evaluation of dysplasia. It seems to be helpful in identifying patients at risk, perhaps before the development of clear dysplasia.

Correlation between neovascularisation and neuroendocrine differentiation in prostatic carcinoma

Neuroendocrine (NE) differentiated tumor cells are found in almost all prostatic carcinomas. Prostatic carcinomas with a high NE differentiation have a poor prognosis and increased metastatic potential. A relationship between the neovascularisation density in the tumor and the metastatic potential in prostatic carcinoma is well known. NE cells and microvessels were demonstrated immunohistochemically on 102 radical prostatectomy specimens using antibodies against Chromogranin A and CD34. Standard areas (7.9 mm2) of maximal Chromogranin A expression and highest vascularisation were determined and topographically related by light microscopy. Area density of microvessels was evaluated morphometrically. NE tumor cells were present in all prostatic carcinomas studied. High grade prostatic carcinomas expressed significantly more NE tumor cells and exhibited a higher neovascularisation than low grade carcinomas. There was significantly higher neovascularisation in high grade tumors with many, as compared to high grade tumors with few, NE tumor cells. Poorer pathological staging correlated with increased neovascularisation and stronger NE differentiation. A topographical relationship between the area of maximal NE tumor cells and the area of highest neovascularisation was found in 80.4% of all cases. An analysis of variance revealed a large number of NE tumor cells as the only predictor of an increased neovascularisation (p = 0.0006). These observations support the concept that increased neovascularisation is influenced not only by poor pathological grading but also by a high NE differentiation.

[A rare cause of iron deficiency anemia: recurrent hemorrhage from a carcinoid of the jejunum--diagnosis and therapy with enteroscopy]

We report a 66-year-old patient with previously diagnosed iron deficiency anemia. He complained of fatigue, but had no further symptoms. Hemoglobin was 9.1 g/dl. Test for occult blood in stool was positive, but gastroduodenoscopy and colonoscopy revealed no bleeding source. The man was referred to our department for push-type enteroscopy. By enteroscopy we diagnosed a pedunculated, large polyp in the upper jejunum. The polyp seemed to be submucosal, but had some ulcerations on its surface as the probable bleeding source. In the lower parts of the small intestine no further polyps were detected. After endoscopic doppler examination we injected adrenaline into the base of the polyp to prevent bleeding and the polyp was removed by snare without complications. The polyp was diagnosed to be a carcinoid and was removed in sano.

[Remnants of the Mullerian duct. Case report based on a complex urogenital abnormality]

Persistent remnants of the caudal müllerian ducts can manifest in several forms and are often associated with other urogenital disorders, especially hypospadias. Inadequate activity of the müllerian inhibiting factor, in addition to fetal testosterone deficiency, is responsible for this syndrome. The etiology, diagnosis and management of müllerian duct remnants are discussed. A complex case of penile-scrotal hypospadia, hypoplastic prostate gland, testicular ectopia and retrovesical cyst is presented.

[Fatal subileus caused by intestinal amyloidosis in light chain plasmacytoma]

This report concerns a patient with systemic amyloidosis due to a plasmocytoma, in whom massive amyloid depositions in the small bowel caused severe diarrhoea and malabsorption. The excessive amyloid depositions in the lamina muscularis propria of the bowel finally resulted in therapy-resistant motility disturbance and adynamic subileus with fatal outcome.

[Computerized tomography-guided fine needle biopsy. Current perspectives in biopsy diagnosis]

253 cutting needle biopsies from 240 patients (151 men, 89 women; mean age 68 [23-84] years) were reviewed. The biopsies were taken under computed (CT) tomography guidance from various parts of the body (pancreas: n = 48, liver: n = 32, other upper abdominal organs: n = 5, mediastinum: n = 27, lung: n = 37, kidney: n = 13, adrenals: n = 8, retroperitoneum: n = 35, pelvis: n = 37, pleura: n = 4, chest wall: n = 6). The data were evaluated retrospectively. In 86% of cases meaningful clinical information was obtained in the form of a definite diagnosis (74%) or of a presumptive or differential diagnosis (12%). As a rule it was possible to assess the degree of malignancy and to ascertain the exact nature of the condition; the latter was true not only of malignant but also of benign lesions. In the majority of cases this had important implications. In just under 14% of all cases the target area was missed and no diagnosis could be made. To raise the chances of obtaining a representative biopsy multiple punctures were performed in 44% of the CT-guided biopsies. In 61 cases (24%) the diagnosis was checked against further tissue samples and in four cases the diagnosis based on needle biopsy material had to be revised. In all, only two complications were recorded; both were mild and did not require treatment. In terms of diagnostic value, CT-guided fine needle biopsies proved considerably superior to conventional cytological studies of fine needle aspiration material.

[New aspects of early gastric carcinoma]

Between 1st January 1970 and 31st December 1984, 910 total or subtotal resections for gastric cancer were carried out in the Department of Surgery of the University Clinic Mannheim. A work-up of operative specimens showed that 146 patients (16%) had early gastric carcinoma. The patients comprised 97 men and 49 women; the youngest was 31, the oldest 86 years. The following trends were apparent when the 58 patients operated on between 1970 and 1976 were compared with the 68 patients operated on between 1977 and 1982: An increase in early gastric carcinoma is also detectable in younger patients. The previously seen tendency for localisation in the antrum appears to have changed in favour of the upper segments of the stomach. The proportion of the diffuse type rose from 26% in the first group to 44% in the second. The 5-year survival of all patients with early gastric carcinoma was 78.8%. No significant difference could be found between the diffuse and intestinal type. The prognosis of early gastric carcinoma appears to be dependent on the depth of invasion and involvement of the lymph nodes.

[Colon carcinoma pathogenesis. An epidemiological study (author's transl)]

The mean incidence age for rectal carcinoma in women rose significantly in the township of Karlsruhe between 1971-1975 from 61,5 to 70,9 years, while the incidence age for colon carcinoma in men decreased significantly from 67,5 to 65,0 years. In the world incidence statistics of colon carcinoma in males, Karlsruhe ranks 16th (13,2 cases per 100 000 inhabitants), whereas the city ranks second for rectal carcinoma in males (18,5 cases/100 000). Prevalence patterns of gastric, colonic, and rectal carcinoma differ between individual districts of Karlsruhe. Time-related pathogenetic influence factors are discussed in extenso.