Abdominal inflammatory myofibroblastic tumour: Clinicopathological and molecular analysis of 20 cases, highlighting potential therapeutic targets

AIMS

Inflammatory myofibroblastic tumour (IMT) is a rare mesenchymal neoplasm of intermediate malignant potential, occurring at any age and at multiple sites. Epithelioid inflammatory myofibroblastic sarcoma (EIMS) is an aggressive subtype of IMT, typically involving the abdomen. Most IMTs harbour kinase gene fusions, especially involving ALK and ROS1, but 20-30% of IMTs show no detectable translocations. The aim of this study is to further delineate clinicopathological and molecular characteristics of abdominal IMT and discover potential new therapeutic targets.

METHODS AND RESULTS

In 20 IMTs, including four EIMS, RNA fusion analysis was performed, followed by multiplex DNA analysis if no ALK or ROS1 fusion was detected. Fourteen IMTs (70.0%) had an ALK translocation and the fusion partner was identified in 11, including a RRBP1::ALK fusion, not previously described in classical (non-EIMS) IMT. RANBP2::ALK fusion was demonstrated in all EIMS. One IMT had a ROS1 fusion. In all ALK/ROS1 translocation-negative IMTs mutations or fusions - as yet unreported in primary IMT - were found in genes related to the receptor tyrosine kinase (RTK)/PI3K/AKT pathway. Three of four patients with EIMS died of disease [mean survival 8 months (4-15 months)], whereas only one of 14 classical IMT patients succumbed to disease [mean follow-up time 52 months (2-204 months); P < 0.01].

CONCLUSION

This study shows the wide clinical spectrum of abdominal IMTs and affirms the poor prognosis of EIMS, raising discussion about its status as IMT subtype. Furthermore, the newly detected alterations of the RTK/PI3K/AKT pathway expand the molecular landscape of IMTs and provide potential therapeutic targets.

Germinal centres within tumour positive sentinel lymph nodes are positively associated with tumour infiltrating lymphocytes and tertiary lymphoid structures in breast cancer

BACKGROUND

Stromal tumour infiltrating lymphocytes (sTILs) and presence of tertiary lymphoid structures have been proposed as indicators of tumour-related immune response in breast cancer. An increased number of germinal centres (GCs) in lymph nodes is considered a sign of humoral immune reactivity.

AIMS

It is unclear whether a relationship exists between number and size of GCs within tumour positive sentinel lymph nodes (SLNpos), sTILs and tertiary lymphoid structures within matched primary breast cancer and breast cancer subtype.

METHODS

Axillary SLNpos from 175 patients with breast cancer were manually contoured in digitized haematoxylin and eosin stained sections. Total SLN area, GC number and GC area were measured in SLNpos with the largest metastatic area. To correct for SLN size, GC number and GC area were divided by SLN area. sTILs and presence of tertiary lymphoid structures were assessed in the primary breast cancer.

RESULTS

A higher GC number and larger GC area were found in patients with high sTILs (≥2%) (both P < 0.001) and in patients with presence of tertiary lymphoid structures (PGC number = 0.034 and PGC area = 0.016). Triple negative and HER2-positive (N = 45) breast cancer subtypes had a higher GC number and higher sTILs compared to hormone receptor positive, HER2-negative breast cancer (N = 130) (PGC number < 0.001 and PsTILs= 0.001).

CONCLUSION

This study suggests GCs measured within SLNpos might be useful indicators of the humoral anti-tumour immune response in breast cancer. Future studies are needed investigating underlying biological mechanisms and prognostic value of GCs in SLNs.

Histologic re‑evaluation of a population‑based series of renal cell carcinomas from The Netherlands Cohort Study according to the 2022 ISUP/WHO classification

The aim of the present study was to re-evaluate 457 renal cell carcinoma (RCC) cases from the Netherlands Cohort Study on Diet and Cancer (NLCS), a large population-based cohort, according to the new 2022 ISUP, Genitourinary Pathology Society and World Health Organisation (WHO) classifications to assess whether newly recognized subtypes of RCC could be found among these cases. These cases were initially evaluated according to the 2004 WHO classification, the Fuhrman grading system and the 3rd version of the Tumor-Node-Metastasis (TNM). Data on tumor size, laterality and date of diagnosis, among other clinicopathological characteristics, were obtained through record linkage with the Netherlands Cancer Registry and the Pathologisch-Anatomisch Landelijk Geautomatiseerd Archief. Digital slides from the NLCS were reviewed by two urogenital pathologists according to the new ISUP grading and the 2022 WHO classification (5th edition). Immunohistochemistry staining for carbonic anhydrase IX was performed on cases with ambiguous morphology. A total of 373 cases of clear cell RCC (ccRCC), 61 cases of papillary RCC (pRCC), 13 cases of chromophobe RCC, 3 cases of collecting duct carcinoma and 4 cases of oncocytoma were identified. The subtyping showed no discrepancy with the previous diagnoses. A comparison of the WHO/ISUP grading to the original Fuhrman grading showed a similar grading in 245 (56.5%) cases of the total ccRCC and pRCC cases. The staging according to the novel TNM classification 8th edition showed a restaging in 286 cases (65.5%). Lymphovascular (microvascular) invasion (LVI) and tumor necrosis (TN) were present in 14.4% and 33.5% of the total number of cases, respectively. Furthermore, the presence of sarcomatoid differentiation in 5.1% and rhabdoid differentiation in 4.2% of the cases was observed. In conclusion, none of the newly accepted and emerging/provisional RCC entities were identified in the NLCS cases, which could be attributed to the high mean age (71.4 years) at diagnosis of the patients included in the present study. A restaging of the NLCS cases using the TNM 8th edition and regrading using ISUP grading was performed, which showed that it is possible to report on newer features, such as sarcomatoid differentiation and LVI, even in an old sample collection.

Cutaneous metastases of internal malignancies: a single-institution experience

Aims

Cutaneous metastases of internal malignancies occur in 1–10% of cancer patients. The diagnosis can sometimes be challenging, especially in cases with an unknown primary cancer.

Materials and methods

A retrospective case review was performed including all cases of skin metastases from primary internal malignancies diagnosed at the Department of Pathology at the Maastricht University Medical Centre+ from 2007 to 2021. The clinicopathological data were collected and immunohistochemical and molecular diagnostic tests were performed to confirm the primary origin of the metastases.

Results

We identified 152 cases (71 female; 31 male patients) of cutaneous metastases of internal malignancies. 28 patients (20 women and 8 men) were diagnosed with multiple cutaneous metastases. Among the female patients, the most common primary tumour was breast cancer (50% of the cases), followed by lung (13.6%), gynaecological (7.3%), and gastrointestinal origin (7.3%). Among the male patients, the most common primary sites were gastrointestinal and lung origin (altogether, 50% of the cases). In 19 patients, the cutaneous metastasis was the first presentation of a clinically silent internal malignancy (18.6%), of which most (78.9%) represented metastatic lung carcinomas. Finally, metastasizing patterns were different across tumour types and gender.

Conclusion

Breast, lung, gastrointestinal, and gynaecologic cancers are the most common primary tumours demonstrating skin metastases. Infrequently, cutaneous metastases can be the first clinically visual manifestation of an underlying not yet diagnosed internal malignancy; therefore, occasional broad immunohistochemical profiling, molecular clonal analysis, and a continuous high level of awareness are necessary for a precise diagnosis of cutaneous metastases of internal malignancies.

Case Report: An Unusual Cause for Recurrent Hemopericardium in a Patient With Dyspnea

The case concerns a female presenting with dyspnoea resulting from recurrent hemopericardium. Pericardiocentesis, coronary angiography, and extensive laboratory and imaging studies did not reveal the underlying etiology of the hemopericardium. Only after repeat and exploratory surgery, diffuse venous pericardial hemorrhages with localized thrombi typical of angiosarcoma were discovered.

Emerging role of human polyomaviruses 6 and 7 in human cancers

BACKGROUND

Currently 12 human polyomaviruses (HPyVs) have been identified, 6 of which have been associated with human diseases, including cancer. The discovery of the Merkel cell polyomavirus and its role in the etiopathogenesis in the majority of Merkel cell carcinomas has drawn significant attention, also to other novel HPyVs. In 2010, HPyV6 and HPyV7 were identified in healthy skin swabs. Ever since it has been speculated that they might contribute to the etiopathogenesis of skin and non-cutaneous human cancers.

MAIN BODY

Here we comprehensively reviewed and summarized the current evidence potentially indicating an involvement of HPyV6 and HPyV7 in the etiopathogenesis of neoplastic human diseases. The seroprevalence of both HPyV6 and 7 is high in a normal population and increases with age. In skin cancer tissues, HPyV6- DNA was far more often prevalent than HPyV7 in contrast to cancers of other anatomic sites, in which HPyV7 DNA was more frequently detected.

CONCLUSION

It is remarkable to find that the detection rate of HPyV6-DNA in tissues of skin malignancies is higher than HPyV7-DNA and may indicate a role of HPyV6 in the etiopathogenesis of the respected skin cancers. However, the sheer presence of viral DNA is not enough to prove a role in the etiopathogenesis of these cancers.

Navitoclax combined with Alpelisib effectively inhibits Merkel cell carcinoma cell growth in vitro

Background:

Merkel cell carcinoma (MCC) is a highly malignant skin cancer. Despite major treatment improvements during the last decade, up to 50% of patients do not respond to therapy or develop recurrent disease. For these patients, alternative treatment options are urgently needed. Here, we assessed the efficacy of the combination of the BCL-2 inhibitor Navitoclax and the PI3K p110α inhibitor Alpelisib in MCC cell lines.

Methods:

The expression of BCL-2 was assessed by immunohistochemistry in MCC and MCC cell lines. Treatment with Navitoclax and Alpelisib alone and in combination was performed on four MCC cell lines. The decrease of cell viability during treatment was assessed by XTT assay and visualized for the combinations by 3D combinatorial index plotting. The increase of apoptotic cells was determined by cleaved PARP Western blotting and Annexin V staining.

Results:

Some 94% of MCCs and all three MCPyV-positive cell lines showed BCL-2 expression. Navitoclax monotreatment was shown to be highly effective when treating BCL-2-positive cell lines (IC₅₀-values ranging from 96.0 to 323.0 nM). The combination of Alpelisib and Navitoclax resulted in even stronger synergistic and prolonged inhibitions of MCC cell viability through apoptosis up to 4 days.

Discussion:

Our results show that the anti-apoptotic BCL-2 is frequently expressed in MCC and MCC cell lines. Inhibition of BCL-2 by Navitoclax in combination with Alpelisib revealed a strong synergy and prolonged inhibition of MCC cell viability and induction of apoptosis. The combination of Navitoclax and Alpelisib is a novel potential treatment option for MCC patients.

Transgenic short-QT syndrome 1 rabbits mimic the human disease phenotype with QT/action potential duration shortening in the atria and ventricles and increased ventricular tachycardia/ventricular fibrillation inducibility

AIMS

Short-QT syndrome 1 (SQT1) is an inherited channelopathy with accelerated repolarization due to gain-of-function in HERG/IKr. Patients develop atrial fibrillation, ventricular tachycardia (VT), and sudden cardiac death with pronounced inter-individual variability in phenotype. We generated and characterized transgenic SQT1 rabbits and investigated electrical remodelling.

METHODS AND RESULTS

Transgenic rabbits were generated by oocyte-microinjection of β-myosin-heavy-chain-promoter-KCNH2/HERG-N588K constructs. Short-QT syndrome 1 and wild type (WT) littermates were subjected to in vivo ECG, electrophysiological studies, magnetic resonance imaging, and ex vivo action potential (AP) measurements. Electrical remodelling was assessed using patch clamp, real-time PCR, and western blot. We generated three SQT1 founders. QT interval was shorter and QT/RR slope was shallower in SQT1 than in WT (QT, 147.8 ± 2 ms vs. 166.4 ± 3, P < 0.0001). Atrial and ventricular refractoriness and AP duration were shortened in SQT1 (vAPD90, 118.6 ± 5 ms vs. 154.4 ± 2, P < 0.0001). Ventricular tachycardia/fibrillation (VT/VF) inducibility was increased in SQT1. Systolic function was unaltered but diastolic relaxation was enhanced in SQT1. IKr-steady was increased with impaired inactivation in SQT1, while IKr-tail was reduced. Quinidine prolonged/normalized QT and action potential duration (APD) in SQT1 rabbits by reducing IKr. Diverse electrical remodelling was observed: in SQT1, IK1 was decreased-partially reversing the phenotype-while a small increase in IKs may partly contribute to an accentuation of the phenotype.

CONCLUSION

Short-QT syndrome 1 rabbits mimic the human disease phenotype on all levels with shortened QT/APD and increased VT/VF-inducibility and show similar beneficial responses to quinidine, indicating their value for elucidation of arrhythmogenic mechanisms and identification of novel anti-arrhythmic strategies.

A digital mRNA expression signature to classify challenging Spitzoid melanocytic neoplasms

Spitzoid neoplasms are a challenging group of cutaneous melanocytic proliferations. They are characterized by epithelioid and/or spindle-shaped melanocytes and classified as benign Spitz nevi (SN), atypical Spitz tumors (AST), or malignant Spitz tumors (MST). The intermediate AST category represents a diagnostically challenging group since on purely histopathological grounds, their benign or malignant character remains unpredictable. This results in uncertainties in patient treatment and prognosis. The molecular properties of Spitzoid lesions, especially their transcriptomic landscape, remain poorly understood, and genomic alterations in melanoma-associated oncogenes are typically absent. The aim of this study was to characterize their transcriptome with digital mRNA expression profiling. Formalin-fixed paraffin-embedded samples (including 27 SN, 10 AST, and 14 MST) were analyzed using the NanoString nCounter PanCancer Pathways Panel. The number of significantly differentially expressed genes in SN vs. MST, SN vs. AST, and AST vs. MST was 68, 167, and 18, respectively. Gene set enrichment analysis revealed upregulation of pathways related to epithelial-mesenchymal transition and immunomodulatory-, angiogenesis-, hormonal-, and myogenesis-associated processes in AST and MST. A molecular signature of SN vs. MST was discovered based on the top-ranked most informative genes: NRAS, NF1, BMP2, EIF2B4, IFNA17, and FZD9. The AST samples showed intermediate levels of the identified signature. This implies that the gene signature can potentially be used to distinguish high-grade from low-grade AST with a larger study cohort in the future. This combined histopathological and transcriptomic methodology is promising for prospective diagnostics of Spitzoid neoplasms and patient management in dermatological oncology.

The curious case of Merkel cell carcinoma: epigenetic youth and lack of pluripotency

Merkel cell carcinoma (MCC) is a very rare, but highly aggressive skin cancer which occurs mainly in elderly patients. MCC cells show an expression pattern of three cell lineages: epithelial, neuroendocrine, and B-cell progenitor. This trilinear expression pattern suggests stemness activity in MCC. The etiopathogenesis of MCC is either linked to the Merkel cell polyomavirus (MCPyV) or in a smaller proportion (20%) to high levels of UV-induced somatic mutations. Both viral presence and accumulation of mutations have been shown to be associated with accelerated DNA methylation Age (DNAmAge) compared to chronological age. The MCC DNAmAge was significantly lower compared to the chronological age, which was irrespective of the viral presence or mutational burden. Although these features indicate some aspects of stemness in MCC cells, gene-expression-based pluripotency testing did not provide evidence for pluripotency of MCC cells.

A quarter century of decline of autopsies in the Netherlands

OBJECTIVE

Autopsy rates have been declining worldwide. The present study reports the outcome of a retrospective analysis of all non-forensic autopsies in the Netherlands over a course of 25 years, and compares these with the most recent Dutch study.

METHOD

Retrospectively, 25 years of data on clinical autopsies from the Nationwide Network and Registry of Histo- and Cytopathology in the Netherlands (PALGA) was paired with the mortality registry (Statistics Netherlands).

RESULTS

The crude prevalence of autopsies declined from 7.07% in 1991 to 2.73% in 2015. After adjusting for age at death, there was no difference in autopsy rate between males and females. An increasing age significantly decreased the autopsy rate.

CONCLUSION

In the Netherlands, clinical autopsies have been declining over the last quarter century. Age at death, but not sex, was associated with the autopsy rate. These different results stress the importance of correct collection and analysis methods of data.

Low prevalence of Merkel cell polyomavirus in human epithelial thymic tumors

Background

The etiology of thymic epithelial tumors is unknown. Murine polyomavirus strain PTA has been shown to induce thymomas in mice. Recently, using diverse molecular techniques, we reported the presence of human polyomavirus 7 (HPyV7) in thymic epithelial tumors. In the present study, we investigated the prevalence of Merkel cell polyomavirus (MCPyV) in thymic epithelial tumors.

Methods

Thirty‐six thymomas were screened for MCPyV by PCR and subsequently tested by DNA and RNA in situ hybridization and immunohistochemistry. Twenty‐six thymomas were diagnosed with myasthenia gravis (MG).

Results

MCPyV DNA was detected by PCR in 7 (19.4%) of the 36 thymic epithelial tumors and in six of these, the presence of MCPyV was confirmed by fluorescence situ hybridization. Of these, 3 (28.6%) revealed weak MCPyV LT‐antigen protein expression. In addition, one of the MCPyV positive thymomas tested positive for MCPyV LT RNA with RNAscope. Of interest, two out of the three thymomas that previously tested positive for MCPyV by immunohistochemistry also tested positive for HPyV7. One of the 11 MG‐negative and 2 of the 25 MG‐positive were positive for MCPyV.

Conclusions

MCPyV DNA and MCPyV protein expression can be detected in human epithelial thymoma; however, to a far lesser extent than HPyV7. Our data strongly indicate that because of its infrequent detection and weak expression, MCPyV is unlikely to play an important role in the etiopathogenesis of human thymomas.

Genomic Landscape of Spitzoid Neoplasms Impacting Patient Management

Spitzoid neoplasms are a distinct group of melanocytic proliferations characterized by epithelioid and/ or spindle shaped melanocytes. Intermediate forms that share features of both benign Spitz nevi (SN) and Spitz melanoma, i.e., malignant Spitz tumor (MST) represent a diagnostically and clinically challenging group of melanocytic lesions. A multitude of descriptive diagnostic terms exist for these ambiguous lesions with atypical Spitz tumor (AST) or Spitz tumor of uncertain malignant potential (STUMP) just naming two of them. This diagnostic gray zone creates confusion and high insecurity in clinicians and in patients. Biological behavior and clinical course of this intermediate group still remains largely unknown, often leading to difficulties with uncertainties in clinical management and prognosis. Consequently, a better stratification of Spitzoid neoplasms in benign and malignant forms is required thereby keeping the diagnostic group of AST/STUMP as small as possible. Ancillary diagnostic techniques such as immunohistochemistry, comparative genomic hybridization, fluorescence in situ hybridization, next generation sequencing, micro RNA and mRNA analysis as well as mass spectrometry imaging offer new opportunities for the distinct diagnosis, thereby allowing the best clinical management of Spitzoid neoplasms. This review gives an overview on these additional diagnostic techniques and the recent developments in the field of molecular genetic alterations in Spitzoid neoplasms. We also discuss how the recent findings might facilitate the diagnosis and stratification of atypical Spitzoid neoplasms and how these findings will impact the diagnostic work up as well as patient management. We suggest a stepwise implementation of ancillary diagnostic techniques thereby integrating immunohistochemistry and molecular pathology findings in the diagnosis of challenging ambiguous Spitzoid neoplasms. Finally, we will give an outlook on pending future research objectives in the field of Spitzoid melanocytic lesions.

Characterization of the thymus in Lrp4 myasthenia gravis: Four cases

Myasthenia gravis (MG) is an autoimmune disease of the neuromuscular junction. Most patients have pathogenic autoantibodies against the acetylcholine receptor (AChR). In the last years a novel subpopulation of MG patients has been described that harbors antibodies against low-density lipoprotein receptor-related protein 4 (Lrp4), another postsynaptic neuromuscular antigen. In early-onset AChR MG (EOMG), the thymus plays an important role in immunopathogenesis, and early thymectomy is beneficial. It is still unknown if the thymus plays any role in Lrp4-MG. In this pilot study, we compared thymus samples from four patients with Lrp4-MG (one pre-treated with immunosuppressive drugs), four non-MG controls and five EOMG patients (not pretreated with immunosuppressive drugs). Immunohistochemistry of the Lrp4-MG thymi revealed normal architecture, with normal numbers and distribution of B-cells, lymphoid follicles and Hassall's corpuscles. Primary CD23⁺ lymphoid follicles were similarly infrequent in Lrp4-MG and control thymic sections. In none of the control or Lrp4-MG thymi did we find secondary follicles with CD10⁺ germinal centers. These were evident in 2 of the 5 EOMG thymi, where primary lymphoid follicles were also more frequent on average, thus showing considerable heterogeneity between patients. Even if characteristic pathological thymic changes were not observed in the Lrp4 subgroup, we cannot exclude a role for the thymus in Lrp4-MG pathogenesis, since one Lrp4-MG patient went into clinical remission after thymectomy alone (at one year follow-up) and one more improved after thymectomy in combination with immunosuppressive therapy.

Phosphatidylinositol 3-kinase p110δ expression in Merkel cell carcinoma

The prognosis of stage III/IV Merkel cell carcinoma (MCC) is very poor. The Phosphatidylinositol 3-kinase p110δ specific inhibitor idelalisib has recently been reported to induce complete clinical remission in a stage IV MCC patient. Here we assessed the expression of p110δ in primary MCC and MCC cell lines including its functionality. Immunofluorescence microscopy revealed a specific cytoplasmic p110δ expression in 71.4% of the tested MCCs and in all tested MCC cell lines. Compared to the B cell leukemia cell line REH all MCC cell lines, except MKL-1, revealed a lower response towards the treatment with idelalisib. MKL-1 showed a 10-fold higher IC₅₀ compared to REH which was accompanied by a significant decrease of Akt phosphorylation. However, treating the MCC cells with the specific PI3K p110α subunit inhibitor BYL719 led to a more effective decrease of the cell viability compared to idelalisib: WaGa cells 30-fold, PeTa cells 15-fold and all other MCC cell lines 3-fold. Although PI3K p110δ is expressed in the majority of MCCs and cell lines its inhibition by idelalisib alone does not suffice to effectively affect MCC cells viability.

Epidemiology, biology and therapy of Merkel cell carcinoma: conclusions from the EU project IMMOMEC

Merkel cell carcinoma (MCC) is a highly aggressive, often lethal neuroendocrine cancer. Its carcinogenesis may be either caused by the clonal integration of the Merkel cell polyomavirus into the host genome or by UV-induced mutations. Notably, virally-encoded oncoproteins and UV-induced mutations affect comparable signaling pathways such as RB restriction of cell cycle progression or p53 inactivation. Despite its low incidence, MCC recently received much attention based on its exquisite immunogenicity and the resulting major success of immune modulating therapies. Here, we summarize current knowledge on epidemiology, biology and therapy of MCC as conclusion of the project 'Immune Modulating strategies for treatment of Merkel Cell Carcinoma', which was funded over a 5-year period by the European Commission to investigate innovative immunotherapies for MCC.

Detection of Merkel Cell Polyomavirus in Seborrheic Keratosis

Seborrheic keratosis (SK) is the most common benign cutaneous neoplasm. A subset shows increased p16 expression. Since SK shares several features with verruca vulgaris, e.g., increased p16 expression, human papillomaviruses (HPV) have been suggested as possible causal agents. However, a relevant association could not be established between HPV and SK. In the present study we aimed to investigate the presence of Merkel cell polyomavirus (MCPyV) in relation to p16 expression in SK. P16 expression was investigated using immunohistochemistry (IHC). Presence of MCPyV was assessed in 23 formalin-fixed paraffin-embedded tissue samples of SK by molecular techniques (i.e., PCR and FISH) and IHC. 16/23 SK showed strong to moderate p16 expression. 6/23 of SK were MCPyV positive by PCR which was confirmed by FISH. Of interest, two samples with strong FISH signals also showed MCPyV expression as tested by IHC. Samples with weaker signal intensity were negative in IHC. P16 expression was not associated with the presence of MCPyV. Concluding, the detection of MCPyV DNA by PCR and FISH in SK reflects the widespread prevalence of MCPyV in the skin. However, low detection rates exclude MCPyV as a major pathogenic factor in SK, most likely representing a coincidental infection. P16 IHC does not appear as useful adjunctive surrogate marker for the presence of MCPyV in SK.

Oncogenic Viruses in Skull Base Chordomas

BACKGROUND

Chordomas are rare tumors assumed to derive from notochordal remnants. We believe that a molecular switch is responsible for their malignant behavior. The involvement of oncogenic viruses has not been studied, however. Thus, in the present study, we investigated the presence of oncogenic viruses in chordomas.

METHODS

DNA and RNA from snap-frozen chordoma (n = 18) and chondrosarcoma (n = 15) specimens were isolated. Real-time PCR or RT-PCR was performed to assess the presence of multiple oncogenic viruses, including herpesviridea (herpes simplex virus [HSV]-1, HSV-2, Epstein-Barr virus [EBV], cytomegalovirus, human herpesvirus [HHV]- 6, HHV-7, and Kaposi's sarcoma-associated herpesvirus), polyomaviridea (parvovirus B19 [PVB19], BK virus, JC virus, Simian virus 40, Merkel cell polyomavirus, human polyomavirus [HPyV]-6, and HPyV-7), papillomaviridae, and respiratory viruses. Immunohistochemistry (IHC) and in situ hybridization (ISH) were used to validate the positive results.

RESULTS

PVB19 DNA was detected in 4 of 18 chordomas (22%) and in 1 of 15 chondrosarcomas (7%). IHC recognizing the VP2 capsid protein of PVB19 showed a positive cytoplasmic staining in 44% of the cases (14 of 32). HHV7 DNA was present in 6 of the 18 chordomas (33%). Genomic DNA of EBV was found in 22% of the samples; however, no positive results were found on ISH. None of the chordoma cases showed any presence of DNA from the remaining viruses.

CONCLUSIONS

Viral involvement in the etiology of chordomas is likely, with PVB19 the most distinguishing.

Cyr61 Expression Pattern and Association with Clinicopathological Factors in Patients with Cervical Cancer

BACKGROUND/AIM

The pro-angiogenic Cyr61 protein has been associated with tumorigenesis and cancer progression in different gynecological carcinomas. In this study, we evaluated the potential impact and clinical relevance of Cyr61 expression in patients with primary non-metastatic cervical cancer (CC).

PATIENTS AND METHODS

Cyr61 expression was assessed in tissue specimen of 48 patients with primary CC by immunohistochemical analysis. Expression levels were scored and correlated to clinico-pathological factors and outcome data.

RESULTS

High Cyr61 expression levels were present in 54.2% of CC tissues. Associations with histological grade (p=0.030), depth of tumor invasion (p=0.007) and GOG score (p=0.027) were observed. Patients who overexpressed Cyr61 displayed an increased death rate (30.8% vs. 18.2%) and a decreased 5-year-survival (76.9% vs. 86.4%).

CONCLUSION

Our data indicate a potential functional impact of Cyr61 in development and the progression of CC. The definite tumor-relevant function (suppressive/promoting) of Cyr61 in CC and the prognostic relevance of Cyr61 overexpression has to be evaluated in larger cohorts.

Anti-Phosphohistone H3-Positive Mitoses Are Linked to Pathological Response in Neoadjuvantly Treated Breast Cancer

BACKGROUND

We evaluated breast cancer (BC) core biopsies taken before neoadjuvant chemotherapy (NACT) by immunohistochemistry using anti-phosphohistone H3 (PHH3) antibody to determine mitosis, and correlated the results to clinicopathological data and histopathological regression of resected tumor specimens after NACT.

METHODS

72 patients with either triple-negative (TN) or luminal type BC received NACT with epirubicin/cyclophosphamide (EC) and Taxotere®. Tumor regression was analyzed in resected specimens; pathological complete response (pCR) was achieved in 22.2%. Immunohistochemistry with PHH3 was performed on biopsy samples taken before treatment, and mitotic figures were evaluated in 10 high-power fields (HPF).

RESULTS

PHH3-detected mitoses correlated significantly with tumor grading (p = 0.001). TNBC showed > 10 PHH3-positive mitoses/10 HPF significantly more frequently than luminal type BC (p = 0.003). Tumors with > 10 PHH3-positive mitoses/10 HPF achieved pCR significantly more often than those with ≤ 10 PHH3-positive mitoses/10 HPF (p = 0.031). Even luminal type BC with > 10 PHH3-positive mitoses/10 HPF was associated significantly with pCR compared to luminal type BC with ≤ 10 PHH3-positive mitoses/10 HPF (p = 0.016).

CONCLUSION

NACT with EC and Taxotere is suitable for strong proliferating TNBC and luminal BC (> 10 PHH3-positive mitoses/10 HPF). Immunohistochemical determination of mitoses using anti-PHH3 antibody is a simple and robust method for predicting therapy response to NACT in BC tissue.

Merkel cell carcinoma: Epidemiology, prognosis, therapy and unmet medical needs

Merkel cell carcinoma (MCC) is a rare skin cancer that is associated with Merkel cell polyomavirus infection in most cases. Incidence rates of MCC have increased in past decades. Risk factors for MCC include ultraviolet light exposure, immunosuppression and advanced age. MCC is an aggressive malignancy with frequent recurrences and a high mortality rate, although patient outcomes are generally more favourable if the patient is referred for treatment at an early stage. Although advances have been made recently in the MCC field, large gaps remain with regard to definitive biomarkers and prognostic indicators. Although MCC is chemosensitive, responses in advanced stages are mostly of short duration, and the associated clinical benefit on overall survival is unclear. Recent nonrandomised phase 2 clinical trials with anti-PD-L1/PD-1 antibodies have demonstrated safety and efficacy; however, there are still no approved treatments for patients with metastatic MCC. Patients with advanced disease are encouraged to participate in clinical trials for treatment, indicating the largely unmet need for durable, safe treatment within this population.

CT-Guided Percutaneous Transthoracic Needle Biopsies Using 10G Large-Core Needles: Initial Experience

Purpose

Using large-core biopsy needles in CT-guided percutaneous transthoracic needle biopsies (PTNB) may be advantageous in terms of larger specimens, which facilitate more extensive histopathological, immunohistochemical, and molecular examination of tumor tissue. The aim of this study was to evaluate the success rate and safety in CT-guided PTNB using 10G large-core biopsy needles.

Methods and Materials

35 patients with intrathoracic lesions suspected of malignancy underwent CT-guided PTNB using dedicated large-core biopsy needles (10G Spirotome™, Medinvents, Hasselt, Belgium). Location, tumor size, number of pleural passes, number of biopsies, histologic result, and complications (pneumothorax, bleeding) were recorded.

Results

Lesion location varied from pleural to hilar location. Mean tumor size was 3.5 cm (range 0.7–9.2 cm). Only one pleural passage was necessary in all patients. Mean distance from the pleura to the lesion was 2.6 cm (max 9.2 cm). Large-core biopsy (10G) was successful in 88.6 %. Pneumothorax was found in 40 %. Minor intraparenchymal bleeding was present in 14 patients. No major complications were recorded.

Conclusion

Large-core biopsy with 10G did not show higher complication rates compared to literature. It is technically feasible and safe. The obtained larger specimens may especially be helpful for the increasing demands of extensive molecular analysis for stratified patient care.

HNRNP G and HTRA2-BETA1 regulate estrogen receptor alpha expression with potential impact on endometrial cancer

Background

Estrogen receptor alpha (ERa/ESR1) expression is regulated by alternative splicing. Its most frequently detectable exon7 skipping isoform (ERaD7) is a dominant negative variant. Elevated expression of ERaD7 was already detected in endometrial cancer (EC), while its potential prognostic significance has not been characterized so far. Exon7 contains potential binding sites for the two functional splicing regulatory opponents, HNRNPG and HTRA2-BETA1 known to trigger opposite effects on EC outcome.

This study served to elucidate the influence of HNRNPG and HTRA2-BETA1 on ERa exon7 splicing regulation and the impact of ERaD7 concentration on type 1 EC outcome.

Methods

Functional in vitro experiments for HNRNPG and HTRA2-BETA1 in regard to the regulatory impact on endogenous and exogenous ERaD7 splicing were performed. Additionally, real-time PCR determined mRNA levels of ERaD7, HNRNPG and HTRA2-BETA1 in 116 type 1 EC patients.

Results

HNRNPG and HTRA2-BETA1 were found to be specific regulators of ERa exon7 splicing. While HTRA2-BETA1 promoted exon7 inclusion, HNRNPG antagonized this effect by inducing exon7 skipping (p = 0.004). ERaD7 was detected in 71 out of 116 type 1 EC specimens. Statistical analyses revealed an inverse correlation between ERaD7 mRNA levels and tumor grading (p = 0.029), FIGO stage (p = 0.033) as well as lymph node metastases (p = 0.032), respectively. Furthermore, higher ERaD7 expression could be correlated to an improved disease-specific survival (p = 0.034).

Conclusions

Our study demonstrates antagonistic regulatory effects of HNRNPG and HTRA2-BETA1 on ERa exon7 splicing with potential impact on type 1 EC clinical outcome due to the consecutively variable expression levels of the ERa isoform D7.

Electronic supplementary material

The online version of this article (doi:10.1186/s12885-015-1088-1) contains supplementary material, which is available to authorized users.

Cells of origin in skin cancer

Adult skin stem cells do not protect their genome by asymmetric chromosome segregation; thus, they are prone to accumulating oncogenic mutations.

BRAFV600E immunopositive melanomas show low frequency of heterogeneity and association with epithelioid tumor cells: a STROBE-compliant article

Treatment of BRAFV600E-mutant melanoma by small molecule inhibitors that target BRAFV600E or MEK kinases is increasingly used in clinical practice and significantly improve patient outcome. However, patients eventually become resistant and therapeutic improvement is required. Molecular diversity within individual tumors (intratumor heterogeneity) and between tumors within a single patient (intrapatient heterogeneity) poses a significant challenge to precision medicine. Using immunohistochemistry, we determined the extent of BRAFV600E intratumor and intrapatient heterogeneity and the influence of morphological heterogeneity in a large series of 171 melanomas of 81 patients. The BRAFV600E mutation rate found in our melanoma series is 44%, with none of 22 (0%) melanoma in situ, 23 of 56 (41%) primary tumors, 28 of 59 (48%) regional metastases, and 24 of 34 (71%) distant metastases harboring the mutation. In general, a diffuse homogeneous immunostaining was seen, even in tumors consisting of more than one cell type, that is, epithelioid, spindle, and/or small cell types. Nevertheless, BRAFV600E-mutant melanomas more often had a purely epithelioid cell population (P=0.063), that is more evident among distant metastases (P=0.014). Only two of 75 (3%) mutated specimens (one primary and one metastasis) displayed heterogeneous BRAFV600E expression. The primary tumor was also morphologically heterogeneous and exclusively displayed BRAFV600E in the epithelioid component, confirming an association between BRAFV600E and epithelioid cells. Twenty-eight of 30 patients (93%) had concordant BRAFV600E mutation status between their tumors. Taken together, BRAFV600E intratumor and intrapatient heterogeneity in melanoma is diminutive, nevertheless, the identified exceptions will have important implications for the clinical management of this disease.

Neoadjuvant chemotherapy in breast cancer significantly reduces number of yielded lymph nodes by axillary dissection

Background

Neoadjuvant chemotherapy (NC) is an established therapy in breast cancer, able to downstage positive axillary lymph nodes, but might hamper their detectibility. Even if clinical observations suggest lower lymph node yield (LNY) after NC, data are inconclusive and it is unclear whether NC dependent parameters influence detection rates by axillary lymph node dissection (ALND).

Methods

We analyzed retrospectively the LNY in 182 patients with ALND after NC and 351 patients with primary ALND. Impact of surgery or pathological examination and specific histomorphological alterations were evaluated. Outcome analyses regarding recurrence rates, disease free (DFS) and overall survival (OS) were performed.

Results

Axillary LNY was significantly lower in the NC in comparison to the primary surgery group (median 13 vs. 16; p < 0.0001). The likelihood of incomplete axillary staging was four times higher in the NC group (14.8% vs. 3.4%, p < 0.0001). Multivariate analyses excluded any influence by surgeon or pathologist. However, the chemotherapy dependent histological feature lymphoid depletion was an independent predictive factor for a lower LNY. Outcome analyses revealed no significant impact of the LNY on local and regional recurrence rates as well as DFS and OS, respectively.

Conclusion

NC significantly reduces the LNY by ALND and has profound effects on the histomorphological appearance of lymph nodes. The current recommendations for a minimum removal of 10 lymph nodes by ALND are clearly compromised by the clinically already established concept of NC. The LNY of less than 10 by ALND after NC might not be indicative for an insufficient axillary staging.

Early B-cell differentiation in Merkel cell carcinomas: clues to cellular ancestry

Merkel cell carcinoma (MCC) is a highly malignant neuroendocrine nonmelanoma skin cancer, which is associated with the Merkel cell polyoma virus (MCPyV). Recently, expression of the terminal deoxynucleotidyl transferase (TdT) and the paired box gene 5 (PAX 5) has been consistently reported in the majority of MCCs. We tested 21 MCCs for the expression of MCPyV, TdT, PAX5, IgG, IgM, IgA, kappa, and lambda by immunohistochemistry and assessed IgH and Igk rearrangement in all 21 MCCs. All of the MCCs revealed specific expression of PAX5 and 72.8% of the MCCs expressed TdT. In addition, most of the MCCs revealed specific expression of one or more Ig subclasses and kappa or lambda. One MCC did reveal monoclonal IgH and Igk rearrangement next to two other MCCs showing Igk rearrangement. As coexpression of TdT and PAX5 under physiologic circumstances is restricted to pro/pre- and pre-B cells we propose, on the basis of our results, that the cell of origin of MCCs is a pro/pre- or pre-B cell rather than the postmitotic Merkel cells. MCPyV infection and transformation of pro-/pre-B cells are likely to induce the expression of simple cytokeratins as has been shown for SV40 in other nonepithelial cells. This model of cellular ancestry of MCCs might impact therapy and possibly helps to understand why approximately 20% of MCCs are MCPyV-negative.

Cellular localization of BARF1 oncoprotein and its cell stimulating activity in human epithelial cell

BARF1 gene encoded by Epstein-Barr virus is capable of immortalizing the primary monkey epithelial cells and of inducing malignant transformation in human EBV-negative B cell lines as well as rodent fibroblast. This oncoprotein is a secreted protein capable of acting as a powerful mitogen. We have studied the effect of BARF1 protein in transfected or BARF1 protein treated human HaCaT epithelial cells. In BARF1-transfected cells, cell growth was activated and its protein was found both in culture medium and cellular compartment (membrane, cytoplasm and nuclei). When purified BARF1 protein was exogenously added in the cell culture medium of HaCaT cells in absence of fetal calf serum led to its entrance into cells and its intracellular localization in cytoplasm, nuclear periphery and nuclei at 14h treatment, determined by confocal and immunoelectron microscopy. Cell fractionation confirmed its nuclear localization. Nuclear localization was observed in both systems. More interestingly, purified BARF1 protein p29 exogenously added in the cell culture medium activated cell passage of G1 to S phase. S phase activation by its autocrine activity and its tumorigenic activity would be associated with the development of EBV-associated carcinomas.

Stromal CD4/CD25 positive T-cells are a strong and independent prognostic factor in non-small cell lung cancer patients, especially with adenocarcinomas

Within the concert of immune reactions against tumour cells cytotoxic and regulatory T-cells are of utmost importance. Several studies revealed contradictory results on this issue. We therefore focused on functional expression patterns and localization of tumour-infiltrating T-lymphocytes in non-small cell lung cancer (NSCLC) and their impact on patient's survival. 232 curatively operated NSCLC patients were included. After histological reevaluation and construction of tissue-multi-arrays immunohistochemical doublestains for CD3/CD8 and CD4/CD25 were performed to evaluate the total number of T-cells and their subsets of cytotoxic and activated T-cells. Additionally, the localization of the lymphocytes was included in the analysis. Hereby, T-cells within the tumour stroma were regarded as stromal, those among cancer cells as intraepithelial. The number of lymphocytes differed significantly between the histological subtypes being most prominent in large cell carcinomas. Survival analysis showed that high numbers of stromal T-lymphocytes are of beneficial prognostic influence in NSCLC patients. This also proved to be an independent prognostic factor in adenocarcinomas. Thus, in a large and well characterized cohort of NSCLC this is the first study to determine the prognostic value of stromal T-lymphocytes, as these are an independent prognosticator in NSCLC especially in adenocarcinomas whereas intraepithelial T-cells are not.

Basal-like molecular subtype and HER4 up-regulation and response to neoadjuvant chemotherapy in breast cancer

Alteration of gene expression profiles during chemotherapy may predict response to neoadjuvant chemotherapy (NAC) in breast cancer patients. In a prospective cohort study of 32 women with primary invasive breast cancer, we obtained tumor specimens before and after 4 cycles of NAC with epirubicine 90 mg/m2 and cyclophosphamide 600 mg/m2, followed by 4 cycles of docetaxel 100 mg/m2. Total-RNA was extracted from tumor specimens and the whole transcriptome was analyzed with Agilent's 44K single color microarray. Data analysis was performed by GeneSpring v.11 and IBM SPSS v.18. Ten tumors were classified as basal-like and 22 tumors were classified as non-basal-like. Gene expression-based molecular subtype (basal-like vs. non-basal-like) (P=0.003), but not tumor grade (P=0.07), estrogen receptor (P=0.1), progesterone receptor (P=0.6) and HER2 status (P=0.4) predicted pathological complete response to NAC. Specifically, 7/10 basal-like tumors responded to NAC, whereas 19/22 non-basal-like tumors did not respond. Comparing gene expression signatures before and after 4 cycles of NAC, we found that all patients with an initial non-basal-like tumor retained this tumor type, whereas 5/7 basal-like tumors, including all responders, lost this molecular subtype. Complete prediction of response to NAC was achieved with a 21 gene list (P=0.000008). Of note, both the expression and up-regulation of a single gene, i.e. HER4, predicted the response to NAC in 26/32 (81%; P=0.002) and in 23/25 (92%; P<0.001) patients, respectively. These preliminary data indicate that therapy-induced HER4 gene up-regulation may be associated with response to NAC with epirubicine, cyclophosphamide and docetaxel.

Abstract 2717: Detection of Merkel cell polyomavirus in chronic lymphocytic leukemia cells by fluorescence in situ hybridization (FISH)

Background: Merkel cell polyomavirus (MCPyV) is detected in approximately 80% of Merkel cell carcinomas (MCC). A number of previous studies have shown that MCC patients are at a significantly increased risk to develop chronic lymphocytic leukemia (CLL) and vice versa. Until recently, clonal integration and truncating mutations of the Large T antigen (LTAg) of MCPyV were restricted to MCC. We have recently reported the presence of the MCPyV in highly purified tumor cells of CLL (n = 19/70, 27.1%) (Blood. 2010 Sep 3). Of these, six revealed a novel 246 bp deletion in the helicase gene of the LTAg. The presence of MCPyV was confirmed by immunohistochemistry.

Material and Method: Here we aimed to determine the presence of MCPyV by fluorescence in situ hybridization (FISH) analysis in CLL cells in order to evaluate whether MCPyV was integrated or episomal. For this purpose we performed FISH analysis as previously described (Int J Cancer. 2005, 115:419-428) using the MCPyV genome as FISH probe. We tested 2 of the previously reported MCPyV positive CLL cases (EDTA decalcified bone marrow trephines) and MCPyV-positive MCC (n = 5). In addition, we tested MCPyV-negative tumors, e.g. breast and colon cancers. All tissues were formalin-fixed and paraffin-embedded.

Results: Specific MCPyV DNA by FISH analysis was detected in the nuclei of MCPyV-positive CLL and MCC cells. In contrast to particularly punctate FISH signals in MCC indicating viral integration, the nuclear FISH signals of the CLL cases revealed especially granular signals, indicative for integrated MCPyV DNA together with transcribed viral RNA (Int J Cancer. 2008, 122:2656-2664). No signals were obtained by MCPyV FISH in breast or colon cancer specimens.

Conclusion: The specific detection of MCPyV in CLL cells further supports our previous report of a possible involvement of MCPyV in a significant subset of CLL. The specific but rather granular nuclear FISH signals in MCPyV positive CLL cells needs further study to evaluate if it is also generated by co-existing episomal virus copies, by viral RNA or by the decalcification process. In addition, more CLL cases will be analyzed for the presence of MCPyV.

Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2717. doi:10.1158/1538-7445.AM2011-2717

EBV-infection in cardiac and non-cardiac gastric adenocarcinomas is associated with promoter methylation of p16, p14 and APC, but not hMLH1

Background: Epstein–Barr virus (EBV)-associated gastric carcinomas (GC) constitute a distinct clinicopathological entity of gastric cancer. In order to determine underlying distinct aberrant promoter methylation we tested cardiac and non-cardiac GC with regard to the presence of EBV.

Methods: One hundred GC were tested by RNA-in situ hybridization for the presence of EBV by EBV-encoded small RNA (EBER). Aberrant promoter methylation was investigated by methylation-specific real-time PCR for p16, p14, APC and hMLH1. P16 protein expression was assessed by immunohistochemistry.

Results: In our selected study cohort, EBER-transcripts were detected in 19.6% (18/92) of GC. EBV-positive GC revealed significantly more often gene hypermethylation of p16, p14 and APC (p < 0.0001, p < 0.0001 and p = 0.02, respectively) than EBV-negative GC. The majority of GC with p16 hypermethylation showed a p16 protein loss (22/28). In contrast, no correlation between the presence of EBV and hMLH1 hypermethylation was found (p = 0.7). EBV-positive GC showed a trend towards non-cardiac location (p = 0.06) and lower stages (I/II) according to the WHO (p = 0.05).

Conclusion: Hypermethylation of tumor suppressor genes is significantly more frequent in EBV-associated GC compared to EBV-negative GC. Our data add new insights to the role of EBV in gastric carcinogenesis and underline that EBV-associated GC comprise a distinct molecular-pathologic as well as a distinct clinicopathological entity of GC.

EBV-infection in cardiac and non-cardiac gastric adenocarcinomas is associated with promoter methylation of p16, p14 and APC, but not hMLH1

BACKGROUND

Epstein-Barr virus (EBV)-associated gastric carcinomas (GC) constitute a distinct clinicopathological entity of gastric cancer. In order to determine underlying distinct aberrant promoter methylation we tested cardiac and non-cardiac GC with regard to the presence of EBV.

METHODS

One hundred GC were tested by RNA-in situ hybridization for the presence of EBV by EBV-encoded small RNA (EBER). Aberrant promoter methylation was investigated by methylation-specific real-time PCR for p16, p14, APC and hMLH1. P16 protein expression was assessed by immunohistochemistry.

RESULTS

In our selected study cohort, EBER-transcripts were detected in 19.6% (18/92) of GC. EBV-positive GC revealed significantly more often gene hypermethylation of p16, p14 and APC (p<0.0001, p<0.0001 and p=0.02, respectively) than EBV-negative GC. The majority of GC with p16 hypermethylation showed a p16 protein loss (22/28). In contrast, no correlation between the presence of EBV and hMLH1 hypermethylation was found (p=0.7). EBV-positive GC showed a trend towards non-cardiac location (p=0.06) and lower stages (I/II) according to the WHO (p=0.05).

CONCLUSIONS

Hypermethylation of tumor suppressor genes is significantly more frequent in EBV-associated GC compared to EBV-negative GC. Our data add new insights to the role of EBV in gastric carcinogenesis and underline that EBV-associated GC comprise a distinct molecular-pathologic as well as a distinct clinicopathological entity of GC.

Gene expression profiles of lung adenocarcinoma linked to histopathological grading and survival but not to EGF-R status: a microarray study

BACKGROUND

Several different gene expression signatures have been proposed to predict response to therapy and clinical outcome in lung adenocarcinoma. Herein, we investigate if elements of published gene sets can be reproduced in a small dataset, and how gene expression profiles based on limited sample size relate to clinical parameters including histopathological grade and EGFR protein expression.

METHODS

Affymetrix Human Genome U133A platform was used to obtain gene expression profiles of 28 pathologically and clinically annotated adenocarcinomas of the lung. EGFR status was determined by fluorescent in situ hybridization and immunohistochemistry.

RESULTS

Using unsupervised clustering algorithms, the predominant gene expression signatures correlated with the histopathological grade but not with EGFR protein expression as detected by immunohistochemistry. In a supervised analysis, the signature of high grade tumors but not of EGFR overexpressing cases showed significant enrichment of gene sets reflecting MAPK activation and other potential signaling cascades downstream of EGFR. Out of four different previously published gene sets that had been linked to prognosis, three showed enrichment in the gene expression signature associated with favorable prognosis.

CONCLUSIONS

In this dataset, histopathological tumor grades but not EGFR status were associated with dominant gene expression signatures and gene set enrichment reflecting oncogenic pathway activation, suggesting that high immunohistochemistry EGFR scores may not necessarily be linked to downstream effects that cause major changes in gene expression patterns. Published gene sets showed association with patient survival; however, the small sample size of this study limited the options for a comprehensive validation of previously reported prognostic gene expression signatures.

Merkel cell polyomavirus sequences are frequently detected in nonmelanoma skin cancer of immunosuppressed patients

Recently, a new human polyoma virus has been identified in Merkel cell carcinomas (MCC). MCC is a highly aggressive neuroendocrine nonmelanoma skin cancer (NMSC) associated with immunosuppression. Clonal integration of this virus which was termed Merkel cell polyoma virus (MCPyV) was reported in a number of MCC. Squamous cell carcinoma (SCC) and basal cell carcinoma (BCC) are also NMSC and are the most frequent cancers in the setting of immunosuppression. A unique group of 56 NMSC from 11 immunosuppressed patients and 147 NMSC of 125 immunocompetent patients was tested for MCPyV by DNA PCR, targeting the Large T Antigen and the structural Viral Protein 1. NMSC included SCC, BCC and Bowen's disease (BD). In addition, normal skin and 89 colorectal cancers were tested. MCPyV specific sequences were significantly more frequently found in NMSC of immunosuppressed patients compared to immunocompetent patients (p < 0.001). In particular BD and BCC revealed a significant increased association of MCPyV of immunosuppressed patients (p = 0.002 and p = 0.006). Forty-seven of 147 (32%) sporadic NMSC were MCPyV positive. Interestingly, 37.5% (36/96) of sporadic BCC of immunocompetent patients were MCPyV positive. No MCPyV was detected within normal skin and only 3 out of 89 of additionally tested colorectal cancers were MCPyV positive. Our data show that MCPyV is a frequently reactivated virus in immunocompromized patients. How MCPyV contributes to the pathogenesis of NMSC, i.e., BD, SCC and BCC, in immunosuppressed patients and in addition, potentially to the pathogenesis of a subset of sporadic BCC needs further investigations.

Transketolase-like protein 1 (TKTL1) is required for rapid cell growth and full viability of human tumor cells

Cancer cells display high rates of aerobic glycolysis, a phenomenon known as the Warburg effect. Lactate and pyruvate, the end products of glycolysis, are overproduced by cancer cells even in the presence of oxygen. The pentose phosphate pathway (PPP) allows glucose conversion to ribose for nucleic acid synthesis, glucose degradation to lactate, and regeneration of redox equivalents. The nonoxidative part of the PPP is controlled by transketolase (TKT) enzymes. One TKT isoform, the transketolase-like protein 1 (TKTL1) is specifically upregulated in different human cancers and its overexpression predicts a poor patient's survival. This finding implicates that an increased TKTL1 expression may activate the PPP leading to enhanced cancer cell growth and survival. To analyze the functional role of TKTL1 in malignant progression, we inhibited TKTL1 by RNAi technologies in human HCT116 colon carcinoma cells. TKTL1 suppression resulted in a significantly slowed cell growth, glucose consumption and lactate production. In TKTL1 knockdown-cells, the intracellular reactive oxygen species levels were not significantly increased, whereas the sensitivity towards oxidative stress-induced apoptosis was clearly enhanced. These data provide new clues on the importance of TKTL1 dys-regulation in tumor cells and indicate that TKTL1 overexpression may be considered not only as a new tumor marker but also as a good target for anticancer therapy.

Frequent detection of Merkel cell polyomavirus in human Merkel cell carcinomas and identification of a unique deletion in the VP1 gene

Merkel cell carcinoma (MCC) is a rare but very aggressive human malignancy of the elderly or immunosuppressed patients. Recently, the clonal integration of a new human polyoma virus, which was termed Merkel cell polyomavirus (MCPyV), has been reported in 8 of 10 MCC patients. In the present study, we studied the formalin-fixed and paraffin-embedded tissue specimens of 39 MCC for the presence of MCPyV by PCR. We applied four different primer sets directed against the large T antigen and the VP1 gene of MCPyV. We were able to detect MCPyV in 77% (n = 30) of MCC as confirmed by sequence analyses of the PCR products. Sequence analyses showed only minor nucleotide changes compared with the previously published MCC sequences. In addition, one patient revealed the amplification of two PCR products using PCR primers directed against the VP1 gene. Sequence analyses confirmed the presence of the expected 351-bp PCR product and in addition a second PCR product of 261 bp containing a unique 90-bp deletion in the VP1 gene, which will lead to a predicted loss of 28 amino acids. The unique 90-bp deletion within the VP1 gene possibly is a result of incomplete viral integration of MCPyV in the MCC. The presence of MCPyV in the majority of MCC tissue specimens in our study strongly underlines a possible role for MCPyV as an etiologic agent in the carcinogenesis of MCC.

Predictive molecular markers for colorectal cancer patients with resected liver metastasis and adjuvant chemotherapy

BACKGROUND & AIMS

The aims of the study were to evaluate the predictive value of 8 candidate molecular markers for colorectal cancer (CRC) patients receiving hepatic arterial infusion (floxuridine [FUDR] and dexamethasone) and systemic irinotecan (CPT11) post resection of liver metastasis.

METHODS

RNA was extracted from microdissected tumor cells of fixed and embedded specimens of resected liver metastases (94 cases) and analyzed by quantitative reverse-transcription polymerase chain reaction (RT-PCR) for thymidine phosphorylase, dihydropyrimidine dehydrogenase, thymidylate synthase, uridine phosphorylase, uridine/cytidine (monophospho)kinase, Bcl-2 related protein, Cyclin-D1, and Survivin expression. Uni- and multivariate statistical analyses and an explorative hierarchical clustering analysis of quantitative RT-PCR data were performed for overall survival and recurrent disease.

RESULTS

After adjustment for multiple clinicopathologic parameters, none of the markers were significantly associated with overall survival (except, marginally, Cyclin-D1; P = .06) or extrahepatic recurrence. However, high Survivin (P = .03) and Cyclin-D1 (P = .05) levels were predictive for hepatic recurrence. Hierarchical cluster analysis identified 7 of 94 patients associated with lower hepatic recurrence (P < .001). This patient group was characterized by low Cyclin-D1 and Survivin messenger RNA levels, both genes also clustering together.

CONCLUSIONS

Cyclin-D1 and Survivin messenger RNA analyzed by standardized, quantitative RT-PCR are predictive markers for CRC patients receiving hepatic arterial infusion (FUDR/dexamethasone) and systemic CPT11 post resection of liver metastasis. Moreover, our exploratory hierarchical cluster analysis of quantitative RT-PCR data supports its potential as an application to define clinically relevant patient subgroups.

Transketolase protein TKTL1 overexpression: A potential biomarker and therapeutic target in breast cancer

Malignant tumors degrade glucose to lactate even in the presence of oxygen via the pentose phosphate pathway (ppp). The non-oxidative part of the ppp is controlled by thiamine-dependant transketolase enzyme reactions. Overexpression of the transketolase-like-1-gene (TKTL1) in urothelial and colorectal cancer is associated with poor patient outcome. We analyzed the expression of the TKTL1 protein in a retrospective institution-based patient cohort with invasive breast cancer by immunohistochemical analysis of 124 paraffin-embedded breast cancer tissues. Our study revealed TKTL1 expression in 86% of breast cancer specimens with 45% showing high expression levels. In contrast, only 29% of corresponding non-neoplastic breast tissues were TKTL1 immunopositive, including 9% with high expression levels. High expression levels of TKTL1 correlated significantly to Her2/neu overexpression (p=0.015). However, TKTL1 expression failed to reach statistical significance for other common prognostic parameters. In contrast to recent data for e.g. colorectal cancer TKTL1 overexpression did not correlate to patient outcome and survival. However, in the context of novel insights into TKTL1-related tumor metabolism and the high proportion of TKTL1 overexpressing breast cancers, this enzyme represents a potential candidate for targeted inhibition of tumor growth in this tumor entity.

Transketolase protein TKTL1 overexpression: A potential biomarker and therapeutic target in breast cancer

Malignant tumors degrade glucose to lactate even in the presence of oxygen via the pentose phosphate pathway (ppp). The non-oxidative part of the ppp is controlled by thiamine-dependant transketolase enzyme reactions. Overexpression of the transketolase-like-1-gene (TKTL1) in urothelial and colorectal cancer is associated with poor patient outcome. We analyzed the expression of the TKTL1 protein in a retrospective institution-based patient cohort with invasive breast cancer by immunohistochemical analysis of 124 paraffin-embedded breast cancer tissues. Our study revealed TKTL1 expression in 86% of breast cancer specimens with 45% showing high expression levels. In contrast, only 29% of corresponding non-neoplastic breast tissues were TKTL1 immunopositive, including 9% with high expression levels. High expression levels of TKTL1 correlated significantly to Her2/neu overexpression (p=0.015). However, TKTL1 expression failed to reach statistical significance for other common prognostic parameters. In contrast to recent data for e.g. colorectal cancer TKTL1 overexpression did not correlate to patient outcome and survival. However, in the context of novel insights into TKTL1-related tumor metabolism and the high proportion of TKTL1 overexpressing breast cancers, this enzyme represents a potential candidate for targeted inhibition of tumor growth in this tumor entity.

The role of Epstein-Barr virus in acute and chronic hepatitis

BACKGROUND/AIMS

Epstein-Barr virus has a seroprevalence of more than 80% world wide and is known to be associated with hepatitis. However, little is known about the underlying pathogenesis and immunmechanisms and no standard diagnostic criteria to diagnose EBV-hepatitis are available.

METHODS

We collected liver biopsies (n=21) with the tentative diagnosis of EBV induced hepatitis according to pathological changes and traceable EBV genome by PCR. Correlation with serological data revealed acute in seven cases, convalescent in two cases, past EBV infection in six cases. Viral RNA was visualised by in situ hybridisation within nuclei of lymphocytes.

RESULTS

In seven of 68 liver biopsies with the diagnosis 'liver disease of unknown aetiology' EBV genome in the tissue was demonstrated indicating a possible role for EBV in the induction of hepatitis or a trapping of infected lymphocytes within the liver. In a control group of 20 EBV-seropositive patients with steatohepatitis EBV-DNA PCR of the liver tissue was negative. Immunohistochemistry identified CD3 and CD8 positive T-lymphocytes as the main lymphocytic infiltrate in EBV hepatitis.

CONCLUSIONS

EBV hepatitis should be taken into consideration in case of typical histopathological changes and a positive DNA PCR of liver biopsy. Serological confirmation of the diagnosis is inevitable.

Splicing factor Tra2-beta1 is specifically induced in breast cancer and regulates alternative splicing of the CD44 gene

The human CD44 gene undergoes extensive alternative splicing of multiple variable exons positioned in a cassette in the middle of the gene. Expression of alternative exons is often restricted to certain tissues and could be associated with tumor progression and metastasis of several human malignancies, including breast cancer. Exon v4 contains multiple copies of a C/A-rich exon enhancer sequence required for optimal inclusion of the exon and binding to the nucleic acid-binding proteins YB-1 and human Tra2-beta1. Here, we show that hTra2-beta1, a member of the extended family of serine/arginine-rich (SR) splicing factors, enhances the in vivo inclusion of CD44 exons v4 and v5. It increased inclusion of exons v4 and v5 and acted synergistically with YB-1. Activation required the C/A-rich enhancer within exon v4. Several other SR proteins had none or only a slight effect on CD44 exon inclusion. In contrast, SC35 inhibited exon usage and antagonized the effects of Tra2 or YB-1. In a matched pair analysis of human breast cancers and their corresponding nonpathologic tissue controls, we found a significant induction of Tra2-beta1 in invasive breast cancer, both on the RNA and protein levels. Together with our functional data, these results suggest an important role for Tra2-beta1 in breast cancer. Induction of this splicing factor might be responsible for splicing of CD44 isoforms associated with tumor progression and metastasis.

Dominance of CD4+ alpha/beta T-cells and inferior role of innate immune reaction in liver metastases

BACKGROUND

Tumor infiltrating lymphocytes (TIL) are frequently present in human tumors with CD8+(-)T-cells as effector and CD4+ T-cells as helper cells. Despite the well established knowledge about primary tumors, only little is known about metastatic disease, especially for liver metastases. The role of the innate immune system in the tumor defence is still enigmatic.

MATERIALS AND METHODS

We performed a subtyping of TIL in 20 liver metastases. Using immunohistochemistry, CD20+, CD3+, CD56+, CD4+ and CD8+ lymphocytes, gamma/delta-T-cells and alpha/beta-T-cells in the tumor, the peritumoral region, portal tracts and lobules were investigated.

RESULTS

The immune response was highly accentuated in the surroundings of the metastases with only few lymphocytes in the tumor itself. There was a dominance of CD3+(-)CD4+(-)alpha/beta-T-cells with a lower number of CD8+(-)T-cells. The CD4+/CD8+ ratio was 6:1. CD56+(-)NK/NKT-cells and gamma/delta-T-cells were rare. No differences were found between metastases from different primaries or according to the number or diameter of the metastases.

CONCLUSION

TIL are part of an interaction between the metastatic tumor and the liver. Among them CD4+ T-cells seem to have a unique independent function in tumor response. The localization of the immune response in the tumor periphery might be a reason for insufficient tumor defense. A defect in the innate immune system could be a reason for the escape of the metastatic tumor cells from tumor surveillance.

No role for Epstein-Barr virus in Dutch hepatocellular carcinoma: a study at the DNA, RNA and protein levels

Epstein-Barr virus (EBV) has been suggested to play a role in hepatocellular carcinoma (HCC). However, reports on detailed EBV transcript analyses in HCCs are limited. It was shown recently that expression of the transforming BARF1 (BamHI A rightward open reading frame 1) gene of EBV is restricted to latently EBV-infected epithelial malignancies, i.e. nasopharyngeal carcinoma and gastric carcinoma. The aim of this study was to test the presence of EBV in Dutch HCCs. A semiquantitative DNA PCR-enzyme immunoassay (PCR-EIA) for the BamHI W fragment of EBV was used to assess the presence of EBV in frozen and paraffin-embedded tissues of 16 HCCs. In addition, several RNA detection techniques, i.e. nucleic acid sequence-based amplification (NASBA), RT-PCR, RNA in situ hybridization (RISH) and immunohistochemistry (IHC), were applied. Five of 16 HCCs and two of four hepatitis C virus hepatitis samples were weakly positive for EBV DNA by PCR-EIA. Using sensitive RNA transcription techniques, no transcripts were found for BARF1, EBNA-1 and BARTs (BamHI A rightward transcripts) in any of the liver tissues tested. In addition, RISH for EBER1/2 and BARTs and IHC for EBNA-1, LMP-1 and ZEBRA, performed on the paraffin-embedded tissue of the PCR-EIA-positive cases and on adjacent non-neoplastic liver tissues, were negative. The absence of epithelial-specific BARF1 transcripts and other EBV transcripts and proteins in the EBV DNA PCR-positive cases argues strongly against a role for EBV in HCC.