PPM1G promotes cell proliferation via modulating mutant GOF p53 protein expression in hepatocellular carcinoma

The serine/threonine protein phosphatase family involves series of cellular processes, such as pre-mRNA splicing. The function of one of its members, protein phosphatase, Mg2+/Mn2+ dependent 1G (PPM1G), remains unclear in hepatocellular carcinoma (HCC). Our results demonstrated that PPM1G was significantly overexpressed in HCC cells and tumor tissues compared with the normal liver tissues at both protein and RNA levels. High PPM1G expression is associated with shorter overall survival (p < 0.0001) and disease-free survival (p = 0.004) in HCC patients. Enhanced expression of PPM1G increases the cell proliferation rate, and knockdown of PPM1G led to a significant reduction in tumor volume in vivo. Further experiments illustrated that upregulated-PPM1G expression increased the protein expression of gain-of-function (GOF) mutant p53. Besides, the immunoprecipitation analysis revealed a direct interaction between PPM1G and GOF mutant p53. Collectively, PPM1G can be a powerful prognostic predictor and potential drug-target molecule.

Nomogram based on the O-RADS for predicting the malignancy risk of adnexal masses with complex ultrasound morphology

OBJECTIVE

The accurate preoperative differentiation of benign and malignant adnexal masses, especially those with complex ultrasound morphology, remains a great challenge for junior sonographers. The purpose of this study was to develop and validate a nomogram based on the Ovarian-Adnexal Reporting and Data System (O-RADS) for predicting the malignancy risk of adnexal masses with complex ultrasound morphology.

METHODS

A total of 243 patients with data on adnexal masses with complex ultrasound morphology from January 2019 to December 2020 were selected to establish the training cohort, while 106 patients with data from January 2021 to December 2021 served as the validation cohort. Univariate and multivariate analyses were used to determine independent risk factors for malignant tumors in the training cohort. Subsequently, a predictive nomogram model was developed and validated in the validation cohort. The calibration, discrimination, and clinical net benefit of the nomogram model were assessed separately by calibration curves, receiver operating characteristic (ROC) curves, and decision curve analysis (DCA). Finally, we compared this model to the O-RADS.

RESULTS

The O-RADS category, an elevated CA125 level, acoustic shadowing and a papillary projection with color Doppler flow were the independent predictors and were incorporated into the nomogram model. The area under the ROC curve (AUC) of the nomogram model was 0.958 (95% CI, 0.932-0.984) in the training cohort. The specificity and sensitivity were 0.939 and 0.893, respectively. This nomogram also showed good discrimination in the validation cohort (AUC = 0.940, 95% CI, 0.899-0.981), with a sensitivity of 0.915 and specificity of 0.797. In addition, the nomogram model showed good calibration efficiency in both the training and validation cohorts. DCA indicated that the nomogram was clinically useful. Furthermore, the nomogram model had higher AUC and net benefit than the O-RADS.

CONCLUSION

The nomogram based on the O-RADS showed a good predictive ability for the malignancy risk of adnexal masses with complex ultrasound morphology and could provide help for junior sonographers.

ebv-circRPMS1 promotes the progression of EBV-associated gastric carcinoma via Sam68-dependent activation of METTL3

Epstein-Barr virus (EBV) is a tumor virus that is associated with a variety of neoplasms, including EBV-associated gastric carcinoma (EBVaGC). Recently, EBV was reported to generate various circular RNAs (circRNAs). CircRNAs are important regulators of tumorigenesis by modulating the malignant behaviors of tumor cells. However, to date, the functions of ebv-circRNAs in EBVaGC remain poorly understood. In the present study, we observed high ebv-circRPMS1 expression in EBVaGC and showed that ebv-circRPMS1 promoted the proliferation, migration, and invasion and inhibited the apoptosis of EBVaGC cells. In addition, METTL3 was upregulated in GC cells overexpressing ebv-circRPMS1. Mechanistically, ebv-circRPMS1 bound to Sam68 to facilitate its physical interaction with the METTL3 promotor, resulting in the transactivation of METTL3 and cancer progression. In clinical EBVaGC samples, ebv-circRPMS1 was associated with distant metastasis and a poor prognosis. Based on these findings, ebv-circRPMS1 contributed to EBVaGC progression by recruiting Sam68 to the METTL3 promoter to induce METTL3 expression. ebv-circRPMS1, Sam68, and METTL3 might serve as therapeutic targets for EBVaGC.

Hypoxia-induced ebv-circLMP2A promotes angiogenesis in EBV-associated gastric carcinoma through the KHSRP/VHL/HIF1α/VEGFA pathway

EBV-encoded circular RNA LMP2A (ebv-circLMP2A) was found to be expressed in EBV-associated gastric carcinoma (EBVaGC) and associated with distant metastasis and poor prognosis. Angiogenesis is a key step in tumor invasion and metastasis and plays a crucial role in tumor progression. However, it is unclear whether and how ebv-circLMP2A is involved in angiogenesis. In this study, we showed that MVD, HIF1α, and VEGFA expression was increased in EBVaGC mouse xenografts with high expression of ebv-circLMP2A. The expression of ebv-circLMP2A was positively correlated with MVD, HIF1α, and VEGFA expression in clinical samples of EBVaGC. Knockdown of ebv-circLMP2A repressed tube formation and migration of HUVECs and decreased VEGFA and HIF1α expression in cancer cells under hypoxia, while ectopic expression of ebv-circLMP2A reversed these effects. Additionally, knockdown of HIF1α blocked the upregulation of ebv-circLMP2A by hypoxia, and ebv-circLMP2A interacted with KHSRP to enhance KHSRP-mediated decay of VHL mRNA, leading to the accumulation of HIF1α under hypoxia. There was a positive feedback loop between HIF1α and ebv-circLMP2A that promotes angiogenesis under hypoxia. ebv-circLMP2A was essential in regulating tumor angiogenesis in EBVaGC and might provide a valuable therapeutic target for EBVaGC.

Comparative Transcriptome Provides a Systematic Perspective on Epstein-Barr Virus-Associated Gastric Carcinoma Cell Lines

Purpose

Epstein–Barr virus (EBV) is widely recognised to cause various tumours, and EBV-associated gastric carcinoma (EBVaGC) is a special type of GC. It has obviously different clinical features and pathological manifestations from EBV-negative gastric carcinoma, but its progression remains elusive. The underlying cancer progression of viral infection detected by genome-wide transcriptome analysis has been demonstrated in numerous diseases.

Methods

We performed comparative RNA sequencing to identify gene expression signatures between GC and EBVaGC cell lines. The differentially expressed (DE) genes were analysed using gene ontology and pathway enrichment.

Results

A total of 4438 DE mRNAs, 3650 DE long non-coding RNAs (lncRNAs), and 248 DE circular RNAs (circRNAs) were detected in GC cells after EBV infection, most of which were highly related to oncogenesis. Likewise, EBV-coding RNA and non-coding RNA were also well-supplemented in EBVaGC. According to bioinformatics, DE mRNAs may contribute to the completion of EBV-infected host cells and modulate mitosis. Binding to actin and participating in adherens junctions to promote contact between the virus and cells are a potential function of DE lncRNAs. The roles of DE circRNAs were enriched in DNA repair and protein modification, and a typical example of this is acting as an miRNA sponge. The establishment of a circRNA-miRNA-mRNA network helps to determine the key elements in the progression of EBVaGC.

Conclusion

This study is the first to systematically reveal the transcriptome landscape of EBVaGC, which will provide an essential resource for genomic, genetic, and molecular mechanisms in the future.

Epstein-Barr virus-derived circular RNA LMP2A induces stemness in EBV-associated gastric cancer

Cancer stem cells (CSCs) are cancer-initiating cells that are not only a source of tumorigenesis but also the cause of tumour progression, metastasis and therapy resistance. EBV-associated gastric cancer (EBVaGC) is a distinct subtype of gastric cancer with unique clinicopathological and molecular features. However, whether CSCs exist in EBVaGC, and the tumorigenic mechanism of EBV, remains unclear. Here, NOD/SCID mice were injected subcutaneously with the EBVaGC cell line SNU719 and treated with 5-fluorouracil weekly. Successive generations of xenografts yielded a highly malignant EBVaGC cell line, SNU-4th, which displays properties of CSCs and mainly consists of CD44⁺ CD24^- cells. In SNU-4th cells, an EBV-encoded circRNA, ebv-circLMP2A, expression increased and plays crucial roles in inducing and maintaining stemness phenotypes through targeting miR-3908/TRIM59/p53 axis. Additionally, high expression of ebv-circLMP2A is significantly associated with metastasis and poor prognosis in patients with EBVaGC. These findings not only provide evidence for the existence of CSCs in EBVaGC and elucidate the pathogenic mechanism of ebv-circLMP2A in EBVaGC, but also provide a promising therapeutic target for EBVaGC.

Improving pathological early diagnosis and differential biomarker value for hepatocellular carcinoma via RNAscope technology

BACKGROUND

The diagnostic and prognostic values of glypican3 (GPC3) and glutamine synthetase (GS) proteins in hepatocellular carcinoma (HCC) have been reported, but their specificity and sensitivity remain low. Here, we applied RNAscope to improve HCC early pathological and differential diagnosis by estimating GPC3 and GS mRNAs.

METHODS

We performed RNAscope and immunohistochemistry (IHC) to detect GPC3 and GS biomarkers on the tissue sections of 194 cases, including high- and low-grade liver dysplastic nodules; highly, moderately, and poorly differentiated HCCs; intrahepatic cholangiocarcinomas (ICCs); metastatic HCC; and carcinomas from other organs.

RESULTS

The results showed that all the cases that were negative for GPC3 by RNAscope were also negative for this protein by IHC. The use of RNAscope assay improved the GPC3 and GS specificity and sensitivity by 20-30%. Hence, HCC shows early recognition and upgrades the metastatic HCC differentiation by 23% compared with IHC (p = 0.0001, 0.0064). Meanwhile, all liver cirrhosis, cholangiocytes and non-HCC samples were negative for GPC3 and GS except lymphocytes in lymphomas, and 2 (8.3%) out of the 24 ICC samples but not in the cancer cells.

CONCLUSION

RNAscope for GPC3 and GS panel was highly specific and sensitive for the pathological identification of dysplastic nodules, early stages of HCCs, and would differentiate them from HCCs and metastatic tumors compared with IHC.

Oral Taodan granules for mild-to-moderate psoriasis vulgaris: protocol for a randomized, double-blind, multicenter clinical trial

Background

Psoriasis is a common chronic inflammatory skin disease with high recurrence rates and increasing incidence. Patients require long-term medication to reduce symptoms and prevent disease progression. Therefore, the development of treatments with high efficiency and low rate of adverse events is of utmost importance. Traditional Chinese medicine (TCM) plays an outstanding role in reducing disease symptoms and improving quality of life. The aim of this trial is to clarify the treatment efficacy, safety, and control of disease recurrence in patients with psoriasis with blood-stasis syndrome treated with Taodan granules (TDKL).

Methods

This trial is a five-center, randomized, double-blind, placebo-controlled study planned to transpire between September 1, 2019, and December 31, 2021. A sample size of 216 participants (108 per group) with mild-to-moderate psoriasis will be randomly assigned to receive TDKL or placebo twice per day, 7 days per week, for 8 weeks. The study duration will be 17 weeks, including a 1-week screening period, 8 weeks of intervention, and another 8 weeks of follow-up. The primary outcomes are improvement in the Psoriasis Area and Severity Index score and recurrence rate after 8 weeks of treatment. Secondary outcomes include body surface area affected and the scores for the Physician Global Assessment, Dermatology Life Quality Index, pain-related quality of life, pain on the visual analogue scale, and TCM syndromes. The number, nature, and severity of adverse events will be carefully recorded.

Discussion

The study results will help clarify the safety and efficacy of TDKL as treatment for psoriasis with respect to both disease regression and recurrence rate. We expect that this study will provide high-quality evidence with important public health implications that may alter the approach to psoriasis management in China.

Trial registration

The trial has been registered at ClinicalTrials.gov (ID: NCT03942198).

The roles of EBV-encoded microRNAs in EBV-associated tumors

Epstein-Barr virus (EBV) is believed to be a pathogen causing a number of human cancers, but the pathogenic mechanisms remain unclear. An increasing number of studies have indicated that EBV-encoded microRNAs (EBV miRNAs) are expressed in a latency type- and tumor type-dependent manner, playing important roles in the development and progression of EBV-associated tumors. By targeting one or more genes of the virus and the host, EBV miRNAs are responsible for the deregulation of a variety of viral and host cell biological processes, including viral replication, latency maintenance, immune evasion, cell apoptosis and metabolism, and tumor proliferation and metastasis. In addition, some EBV miRNAs can be used as excellent diagnostic, prognostic and treatment efficacy predictive biomarkers for EBV-associated tumors. More importantly, EBV miRNA-targeting therapeutics have emerged and have been developing rapidly, which may open a new era in the treatment of EBV-associated tumors in the near future.

Identification of virus-encoded circular RNA

Circular RNAs (circRNAs) are a novel class of non-coding RNA molecules in eukaryotic organisms that have potentially important roles in gene regulation. Nevertheless, whether viruses can encode circRNA is still uncertain. To examine whether large genome DNA viruses can generate circRNA during the infection of human cells, we performed RNA sequencing of ribosomal RNA-depleted total RNA from Epstein-Barr virus (EBV)-infected cell lines, including SNU-719, AGS-EBV, C666-1 and Akata. We identified an EBV-encoded circRNA, ebv_circ_RPMS1, that consists of the head-to-tail splicing of exons 2-4 from the RPMS1 gene. Furthermore, we demonstrated that ebv_circ_RPMS1 was localized in both cytoplasm and nuclei. Given that circRNAs shape gene expression by titrating microRNAs, regulating transcription and/or interfering with splicing, we identified a novel viral regulator of host and/or viral gene expression.

[BRAF V600E mutation and clinicopathologic characteristics in 250 cases of brain tumors associated with epilepsy]

Objective: To investigate the clinicopathologic characteristics and BRAF V600E mutation of brain tumors associated with epilepsy. Methods: Totally 250 patients with brain tumors associated with epilepsy were included from March 2008 to August 2017 retrospectively at Sanbo Brain Hospital, Capital Medical University.The clinical manifestations, histological features and BRAF V600E mutation results were collected and analyzed. Results: There were 132 males and 118 females, and the male to female ratio was 1.1∶1.0. The age of patients ranged from 2 to 67 years(mean 22 years). The tumors had obvious local space occupying effect on MRI. The temporal lobe was the most common site (44.4%, 111/250). There were 58.4% (146/250) of ganglioglioma (GG), 24.0% (60/250) of dysembryoplastic neuroepithelial tumor (DNT), 12.8% (32/250) of pleomorphic xanthoastrocytoma(PXA), 4.0% (10/250) of angiocentric glioma (AG) and 0.8% (2/250) of papillary glioneuronal tumor (PGNT). Mixed GG, PXA and DNT morphological structures were found in 9 of patients. Among 250 cases, 35 cases were accompanied by focal cortical dysplasia(FCD). BRAF V600E was seen in 43 of 74 (58.1%) GG and 13 of 28 (46.4%) PXA. The most common pathologic grade of GG, DNT, AG and PGNT was WHO I. Some of the tumor cells from GG (34 cases) showed higher proliferative activity (WHO Ⅱ/Ⅲ). Most cases of PXA were WHOⅡand high proliferative activity was seen in nine cases. Conclusions: The association of low-grade glioneuronal tumors with intractable epilepsy was well-recognized. The most common low-grade glioneuronal tumors were GG.GG may occur in any part of the central nervous system, with a predilection for temporal lobe. Each type of low-grade glioneuronal tumors has its own unique histological morphology, but some may show complex features with 2 or 3 mixed components. The occurrence of BRAF V600E mutations in GG is common, and their detection may be valuable for the diagnosis and treatment in GG.

[Abnormality of TOP2A expression and its gene copy number variations in neuroblastic tumors]

Objective: To detect TOP2A protein expression and gene copy number alterations, and to analyze related clinical and pathological implications in pediatric neuroblastic tumors (NT). Methods: Immunohistochemistry was used to detect TOP2A protein expression. Fluorescence in situ hybridization (FISH) was used to detect numerical aberrations of TOP2A. Results: TOP2A protein was expressed in 59.1%(52/88) of cases, which was associated with differentiation (P=0.006), Ki-67 index (P<0.01) and MKI (P=0.001). Twenty-eight cases (35.0%, 28/88) showed TOP2A gene amplification, which was correlated with the age (P<0.01), clinical stage (P=0.028), high risk group (P=0.001), Ki-67 index (P=0.040) and differentiation (P=0.014). Survival analysis showed that TOP2A expression was related to survival rate. Multivariate analyses showed that TOP2A expression was an independent predictor for poor prognosis (P=0.010). Conclusions: More than half of the cases show TOP2A expression, which is more likely associated with NB, high Ki-67 index and high MKI. Cases with TOP2A expression have shorter survivals and poorer prognosis. TOP2A amplification is seen in 35% and likely occurs in patients older than 18 months and at advanced INSS stages (Ⅲ and Ⅳ). As a target of the anthracycline-based adjuvant drugs, TOP2A test can be used to select patient with NT for the therapy.

[N-myc gene copies in children with neuroblastoma and its clinical significance]

This study was purposed to analyze the relation of N-myc gene copy number with clinical staging, pathological types and tumor biological factors in children with neuroblastoma (NB), and to investigate the influence of chemotherapy on N-myc gene expression and explore the relationship of N-myc gene copies with prognosis of NB children. The newly diagnosed children with NB from 1 March 2007 to 31 January 2011 were enrolled in this study. The treatment was carried out by BCH-NB-2007 based on Hongkong NB-07 protocol, and the patients were follow up to 31 January 2012. The N-myc gene in NB children was detected by FISH. According to number of N-myc gene copies, the NB children were divided into 3 groups. A group (N-myc gene negative) had less than 2 copies, B group (N-myc gene gains) had 3 to 9 copies, and C group (N-myc amplification) had more than 10 copies. The results showed that the N-myc gene expression in 58 cases of NB was observed. There were 36 males and 22 females. NB children aged from 6.5 to 138 months (median age 47.5 months), all patients were followed up for 11 - 57 months with an average of 31.5 months. INSS stages I-IV were 1, 5, 8 and 44 cases, respectively. Twenty-five cases had primary post mediastinal tumor, thirty-three cases had retroperitoneal and pelvic tumor, three of which also companied with post mediastinal tumor. Thirty-five cases had bone metastasis (60.3%), thirty-two cases had bone marrow metastasis (55%). Of the 54 patients with fully known biologic features, seventeen cases had ganglioneuroblastoma, thirty-seven cases had neuroblastoma (15 displayed differentiated, 7 poorly differentiated or undifferentiated, 15 with pathological changes after chemotherapy), four cases had bone marrow metastasis only detected by bone marrow biopsy. Eleven cases had N-myc gene negative, forty-three had N-myc gains, four had N-myc amplification. The average copy number of N-myc gene copies in 58 cases was 5.96 ± 7.81 in which 28 children were non chemotherapy cases, their average copy number was 4.00 ± 1.88, thirty cases out of 58 cases received preoperation chemotherapy (chemotherapy group), and their average copy number was 7.80 ± 10.46, the difference is significant (P = 0.064). The clinic stage, the location of primary tumor, pathological classification, urine VMA and serum neurogenic specific enolase had no effects on the N-myc gene expression, but the serum LDH level had influence (P < 0.01). Single factor Kaplan-Meier analysis showed that the number of N-myc gene copies in NB patients were closely related with the poor prognosis. The more copies of N-myc gene, the more poor prognosis, the difference is statistically significant (P < 0.05). It is concluded that the number of N-myc gene copies correlates with the rapid growth of NB and its poor prognosis, detecting the N-myc amplification can help to estimate the prognosis and decide the program of treatment. Serum LDH, which correlated with the rapid growth of NB, had effect on the N-myc gene expression and is closely related with the poor prognosis of NB.

Detection of C-MYC oncogene translocation and copy number change in the normal-dysplasia-carcinoma sequence of the larynx by fluorescence in situ hybridization

The aim of this study was to determine the translocation and copy number change of the C-MYC gene in patients with laryngeal dysplasia and laryngeal squamous cell carcinoma (LSCC), and to evaluate the prevalence of such expression in relation to the normal-dysplasia-carcinoma sequence. Fluorescent in situ hybridization (FISH) was applied on formalin-fixed paraffin-embedded blocks of 93 laryngeal lesion specimens (14 normal epithelium, 15 mild dysplasia, 18 moderate dysplasia, 16 severe dysplasia, 9 carcinoma in situ, and 21 invasive carcinoma). C-MYC translocation was not observed in all laryngeal tissue. The high frequency for C-MYC copy-number increased (100%) in invasive carcinoma: 57.14% amplifications and 42.86% gains, and the positive rate of C-MYC amplification and copy-number change increased with the increasing severity of laryngeal lesions (P < 0.0001). The results suggest that C-MYC may be activated by gain/amplification in LSCC and precancerous lesions. Thus, C-MYC may play an important role in promoting LSCC progression, and early FISH detection of C-MYC may be exploited to set a screening test for laryngeal dysplasia.

[Clinicopathologic features of systemic EBV-positive T/NK-cell lymphoproliferative disease in adults]

OBJECTIVE

To study the clinicopathologic features, immunophenotype, clonality and Epstein-Barr virus (EBV) status of systemic EBV-positive T/NK-cell lymphoproliferative disease in adults (ASEBV(+)T/NK-LPD).

METHODS

Twenty cases of ASEBV(+)T/NK-LPD were analyzed retrospectively with histopathologic review, immunohistochemistry and in-situ hybridization for EBV-encoded RNA (EBER). The follow-up data were collected.

RESULTS

There were altogether 15 males and 5 females. The median age of the patients was 34 years. The average duration from onset of symptoms to diagnosis was 8.7 months. Fever (18/20), hepatosplenomegaly (18/20) and lymphadenopathy (17/20) were the main clinical manifestations. Eleven of the 17 patients died during follow-up, with a mean survival of 2.9 months. Histologically, there was obvious expansion of T zone of the involved lymph nodes, associated with diminished lymphoid follicles. The interfollicular areas were widened and infiltrated by small to median-sized lymphoid cells which showed only mild atypia. Scattered large lymphoid cells were not uncommon. The nodal capsule was thickened in 6 cases. Focal necrosis was seen in 9 cases. Sinus histiocytic proliferation with erythrophagocytosis was observed in 3 cases. In addition, there were mild atypical lymphoid cells infiltrate into the liver, spleen, intestinal mucosa and bone marrow. Immunohistochemical study and in-situ hybridization showed that the EBER-positive cells were of T-cell lineage, with CD3 expression. They were also positive for cytotoxic molecules (granzyme B or TIA-1). Only 1 case was CD56 positive. A predominance of CD8-positive cells was demonstrated in 8 of the 14 cases studied, while CD4-positive cells predominated in the remaining 5 cases. One case showed similar proportion of CD8 and CD4-positive cells. The number of EBER-positive cells ranged from 30 to more than 300 per high-power fields. These EBER-positive cells were of small to large size and located mainly in the expanded T zone and occasionally in the germinal centers. Three of the 7 cases exhibited clonal rearrangement of T-cell receptor gamma gene, while the other 4 cases exhibited polyclonal rearrangement of T-cell receptor gamma gene.

CONCLUSIONS

ASEBV(+)T/NK-LPD is a systemic disease with a subacute or chronic clinical course. Most patients suffer from relapsing fever, lymphadenopathy and hepatosplenomegaly. The disease is characterized by proliferation of EBV-infected cytotoxic T cells. The T zone of the involved lymph nodes shows expansion by mildly atypical lymphoid cells. The disease is associated with poor clinical outcome and can be life-threatening. The patients often die of multiorgan failure and bleeding.

[Molecular genetic features of sporadic Burkitt's lymphoma in children]

OBJECTIVE

To investigate the molecular genetic features and diagnostic aspects of sporadic Burkitt's lymphoma (BL) in children.

METHODS

Tissue microarray was constructed to include 64 cases of pediatric BL and 6 cases of pediatric diffuse large B-cell lymphoma (DLBCL). Immunohistochemistry and fluorescence in-situ hybridization for c-myc, bcl-2, bcl-6, IgH, myc/IgH and bcl-2/IgH gene were performed. Cases of pediatric Burkitt's lymphomas were subclassified into three groups based on their cellular orgins: the germinal center (GC) group, the late-germinal center (late-GC) group and the post-germinal center (post-GC) group.

RESULTS

Among 64 Burkitt's lymphomas studied, expression of CD20, CD10, bcl-6, bcl-2 and MUM1 by immunohistochemistry were 100% (64 cases), 98.4% (63 cases), 96.9% (62 cases), 0 (0 cases) and 23.4% (15 cases), respectively. Various gene rearrangements were found involving the c-myc 93.1% (54/58 cases) and IgH 82.8% (48/58 cases). Detailed rearrangements are as follows: 46 cases (85.2%) myc/IgH gene translocation along with c-myc and IgH gene rearrangement; 4 cases (7.4%) c-myc gene rearrangement without IgH and myc/IgH abnormality; 4 cases (7.4%) without c-myc, IgH or myc/IgH gene rearrangement. No case showed bcl-2 gene abnormality (100%). Fifty nine cases showed normal bcl-6 gene status. One case had bcl-6 gene rearrangement and amplification with the pathologic and immunophenotypic characteristics of BL, leading to a revised pathological diagnosis of B-cell lymphoma, unclassifiable with features intermediate between diffuse large B-cell lymphoma and Burkitt's lymphoma (DLBCL/BL). Two cases showed c-myc gene rearrangement. Two cases showed bcl-6 gene amplification and 6 DLBCL cases had a normal status of bcl-2/IgH.

CONCLUSIONS

A majority of pediatric sporadic BL arise from the germinal center B cells, most of which have c-myc gene rearrangement. It is useful to distinguish BL and DLBCL by multiple genes detection.

[A clinical study of chromosome translocations in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue in Chinese patients]

OBJECTIVE

To investigate the genetic aberrations in extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT) lymphomas from different sites of the body in Chinese patients.

METHODS

Two hundred and seventeen paraffin-embedded MALT lymphoma specimens from 11 major sites were studied with interphase fluorescence in situ hybridization (FISH) to detect t (11; 18) (q21; q21)/API2-MALT1, t (1; 14) (p22; q32)/IGH-BCL10, (14; 18) (q32; q21)/IGH-MALT1 and BCL6 gene involved chromosome translocations.

RESULTS

These translocations were mutually exclusive and detected in 21% (46/217) of the cases, including t (11; 18) (q21; q21) API2-MALT1 13% (29/217), t (1; 14) (p22; q32) IGH-BCL10 in 1% (3/217), t (14; 18) (q32; q21) IGH-MALT1 1% (2/217), BCL6 involved translocation in 2% (4/217) and IGH-unknown translocation partner in 4% (8/217). t (11; 18) (q21; q21) API2-MALT1 was found with the highest frequency in MALT lymphoma from lungs (47%, 8/17) and small intestine (29%, 4/14), followed by salivary gland (17%, 1/6), stomach (14%, 12/84) and ocular adnexae (6%, 4/68). t (1; 14) (p22; q32) was only detected in lungs (12%, 2/17) and stomach (1%, 1/84). t (14; 18) (q32; q21) was mainly detected in lungs (6%, 1/17) and ocular adnexae (2%, 1/68). BCL6 gene involved translocation was detected in salivary gland (17%, 1/6) and stomach (4%, 3/84).

CONCLUSIONS

It is demonstrated that the four translocations occur with markedly variable frequencies in MALT lymphoma of different sites in Chinese patients. The distributions of these chromosome translocations in Chinese patients are slightly different from those reported in western patients.

[Primary ocular adnexal lymphoproliferative lesions: clinicopathologic features and genetic alterations]

OBJECTIVE

To investigate clinicopathological and genetic characteristics of primary ocular adnexal lymphoproliferative lesions.

METHODS

Clinical, morphological and immunohistochemical features of 37 archival cases of primary ocular adnexal lymphoproliferative lesions were studied including 5 cases of reactive lymphoid hyperplasia and 32 lymphomas retrospectively. Classification of the lymphomas were made according to the WHO classification of tumors of haematopoietic and lymphoid tissues. All cases were studied by interphase fluorescence in situ hybridization (FISH) using dual color break apart probes of IgH, MALT1, bcl-6, c-Myc, bcl-2, CCND1, bcl-10, and FOXP1 for detection of chromosomal aberrations involving IgH, MALT1, bcl-6, c-Myc, bcl-2, cyclinD1, bcl-10 and FOXP1 genes, respectively. FISH with IgH / bcl-2 dual color dual fusion probe was used for detection of t(14;18)(q32;q21)/IgH-bcl-2. CEP18 spectrum orange probe was used for detection of aneuploidy of the chromosome 18.

RESULTS

Among 32 cases of lymphomas, 28 cases (87.5%) were extranodal marginal zone B-cell lymphomas of mucosa associated lymphoid tissue (MALT lymphoma), 2 cases were follicular lymphoma (FL) and 2 cases diffuse large B cell lymphoma (DLBCL). Among the 28 cases of MALT lymphoma, chromosomal aberrations were found in 60.7% (17/28) by interphase FISH analysis. One case showed positive IgH break-apart signal with unknown partner. 16 cases showed three copies of different genes, of which, three copies of MALT1, bcl-6, and c-Myc were identified in 7 cases (25%), 12 cases (43%), and 2 cases (8%) of MALT lymphomas, respectively. In addition, 5 cases showed two genes including three copies of bcl-6 and MALT1 in 4 cases, and three copies of bcl-6 together with c-Myc in one case. Furthermore, all cases with three copies of MALT1 had trisomy 18. t(14;18)(q32;q21) was detected in both follicular lymphomas. Of the 2 DLBCL cases, one showed three copies of bcl-6 together with trisomy 18 and the other one showed three copies of bcl-6 together with IgH and c-Myc rearrangements. Chromosomal aberration was not found in all 5 cases of reactive lymphoid hyperplasia.

CONCLUSIONS

The most common entity of primary ocular adnexal lymphomas is MALT lymphoma and FISH is helpful for their differential diagnosis and classification. Trisomy 18 and three copies of bcl-6 are common chromosomal aberrations in primary ocular adnexal MALT lymphomas.