BACKGROUND: Thymic carcinomas (TCs) and thymic neuroendocrine neoplasms (TNENs) are two aggressive subtypes of thymic malignancy. Traditional therapy for advanced TCs and TNENs has limited outcome. New genomic profiling of TCs and TNENs might provide insights that contribute to the development of new treatment approaches. METHODS: We used gene panel sequencing technologies to investigate the genetic aberrations of 32 TC patients and 15 TNEN patients who underwent surgery at Shanghai Chest Hospital between 2015 and 2017. Patient samples were sequenced using a 324-gene platform with licensed technologies. In this study, we focused on clinically relevant genomic alterations (CRGAs), which are previously proven to be pathogenic alterations, to identify the pathology-specific mutational patterns, prognostic signatures of TCs and TNENs. RESULTS: The mutational profiles between TCs and TNENs were diverse. The genetic alterations that ranked highest in TCs were in CDKN2A, TP53, ASXL1, CDKN2B, PIK3C2G, PTCH1, and ROS1 , while those in TNENs were in MEN1, MLL2, APC, RB1 , and TSC2 . Prognostic analysis showed that mutations of ROS1, CDKN2A, CDKN2B, BRAF, and BAP1 were significantly associated with worse outcomes in TC patients, and that mutation of ERBB2 indicated shortened disease-free survival (DFS) and overall survival (OS) in TNEN patients. Further investigation found that the prognosis-related genes were focused on signal pathways of cell cycle control, chromatin remodeling/DNA methylation, phosphoinositide 3-kinases (PI3K)/protein kinase B (AKT)/mammalian target of rapamycin (mTOR), and receptor tyrosine kinase (RTK)/RAS/mitogen-activated protein kinase (MAPK) signaling. CONCLUSION We profiled the mutational features of 47 Chinese patients with thymic malignancy of diverse pathologic phenotypes to uncover the integrated genomic landscape of these rare tumors, and identified the pathology-specific mutational patterns, prognostic signatures, and potential therapeutic targets for TCs and TNENs.
Humans ; Thymoma ; Protein-Tyrosine Kinases/genetics* ; Proto-Oncogene Proteins/genetics* ; China ; Thymus Neoplasms/pathology* ; Prognosis ; Neuroendocrine Tumors/pathology* ; Mutation/genetics*

ACTH Syndrome, Ectopic ; etiology ; Adult ; Carcinoid Tumor ; pathology ; secretion ; Cushing Syndrome ; etiology ; Humans ; Male ; Pro-Opiomelanocortin ; genetics ; Reverse Transcriptase Polymerase Chain Reaction ; Thymus Neoplasms ; pathology ; secretion

OBJECTIVETo study the correlation between amplification of chromosome 1 and histological typing and clinical staging of thymic epithelial tumors according to the WHO classification.

METHODSAmplification of chromosome 1 was detected by interphase fluorescence in-situ hybridization (FISH) in 60 cases of thymic epithelial tumors, including type A thymoma (2 cases), type AB (19 cases), B1 (4 cases), B2 (14 cases), B3 (11 cases), metaplastic thymoma (2 cases), and thymic carcinoma (8 cases) and 11 samples of normal thymus.

RESULTSGain on chromosome 1 was found in 19 cases (31.7%) of thymic epithelial tumors, and none was detected in normal thymic tissues (P < 0.05). The positive rates of gain on chromosome 1 were statistically different among various histological subtypes of thymic epithelial tumors (P < 0.05), in which the highest rate of detection was in thymic carcinoma (6/8), the second, type B3 (6/11), followed by type A (1/2), type AB (4/19), type B2 (2/14) and type B1 (0). The positive rate of gain on chromosome 1 in type B3 had no statistical difference from thymic carcinoma (P > 0.05), but significantly higher than that in other types of thymoma (P < 0.05). In addition, the polysomy rate of chromosome 1 was significantly different among the thymic epithelial tumors at different clinical stages (P = 0.023), and that at stages III and IV was statistically higher than that in stages I and II (P = 0.003) but there was no significant difference between stage I and stage II tumors (P = 0.750).

CONCLUSIONSGain on chromosome 1 is more common in thymic carcinoma and type B3 thymoma than that in other subtypes of thymic epithelial tumors. Thymoma of type B3 may have different genetic features from other subtypes. Detection of gain on chromosome 1 by FISH is helpful in the differential diagnosis and prediction of prognosis in patients with thymic epithelium tumors.

Adult ; Aged ; Carcinoma, Squamous Cell ; genetics ; pathology ; Chromosomes, Human, Pair 1 ; genetics ; Female ; Follow-Up Studies ; Gene Amplification ; Humans ; Male ; Middle Aged ; Neoplasm Staging ; Polyploidy ; Prognosis ; Thymoma ; classification ; genetics ; pathology ; Thymus Neoplasms ; classification ; genetics ; pathology

Germ-line mutations in BRCA2 predispose to early-onset cancer. Homozygous mutant mouse, which has Brca2 truncated in exon 11 exhibit paradoxic occurrence of growth retardation and development of thymic lymphomas. However, due to its large embryonic lethality, cohort studies on the thymic lymphomas were not feasible. With the aid of Cre-loxP system, we demonstrate here that thymus-specific disruption of Brca2 allele without crossing it to p53-mutant background leads to the development of thymic lymphomas. Varying from 16 weeks to 66 weeks after birth, 25% of mice disrupted of Brca2 in the thymus died of thymic lymphomas, whereas previous report did not observe lymphomagenesis using similar Cre-loxP system. Future analysis of thymic lymphomas from these mice presented here will provide information on the cooperative mutations that are required for the BRCA2-associated pathogenesis of cancer.
Animals ; BRCA2 Protein/deficiency/*genetics ; CD4-CD8 Ratio ; Cell Separation ; Flow Cytometry ; Integrases/*genetics/immunology ; Lymphoma/*genetics/immunology/metabolism/pathology ; Mice ; Mice, Knockout ; Organ Specificity ; *Sequence Deletion ; T-Lymphocytes/enzymology/*immunology ; Thymus Gland/immunology/metabolism/pathology ; Thymus Neoplasms/*genetics/immunology/metabolism/pathology ; Tumor Suppressor Protein p53/deficiency/genetics/immunology

OBJECTIVETo study the relationship between activation of pro-MMP-2 and expression of matrix metalloproteinases (MMP)-2, MT1-MMP and tissue inhibitor of metalloproteinases (TIMP)-2 mRNA in thymoma and thymic carcinoma; and to study the molecular mechanism of invasion and metastasis of thymic epithelial tumors.

METHODSFresh tissue specimens of thymoma, thymic carcinoma and normal thymus were included. The mRNA expression of MMP-2, MT1-MMP and TIMP-2 were analyzed by real-time reverse transcription polymerase chain reaction. The pro-MMP-2 activation ratio and its localization were determined by gelatin zymography and film in-situ gelatin-Zymography, respectively. Correlation of mRNA expression of MMP-2, MT1-MMP and TIMP-2 was investigated in tumors with different histological subtypes and clinical stages.

RESULTSThere were no significant differences in the expressions of MMP-2, MT1-MMP and TIMP-2 mRNA between I and II stage or III and IV stage thymomas (P > 0.05). However, significant differences of the expressions were observed between three tumor groups: I-II stage, III-IV stage and thymic carcinomas (P < 0.005), and between three histological subtypes: AB-B1 (lymphocyte-rich and mixed types), B2-B3 (cortical and predominantly polygonal cells types) and thymic carcinomas (P < 0.05). Expression levels of MT1-MMP and TIMP-2 mRNA were correlated with pro-MMP-2 activation ratio (Spearman rank correlation: r = 0.7235, r = 0.7647, P < 0.005). The expression of MMP-9 did not show significant differences between thymomas and thymic carcinomas.

CONCLUSIONSMMP-2, MT1-MMP and TIMP-2 mRNA expression levels are correlated with the histologic subtypes and clinical stages of thymoma. The mRNA expressions of MT1-MMP and TIMP-2 are correlated with the activation ratio of pro-MMP-2. It is speculated that upregulation of MT1-MMP gene expression may induce an activation of pro-MMP-2 through TIMP-2.

Adult ; Aged ; Aged, 80 and over ; Carcinoma, Squamous Cell ; enzymology ; metabolism ; pathology ; Enzyme Activation ; Female ; Humans ; Male ; Matrix Metalloproteinase 2 ; biosynthesis ; genetics ; Matrix Metalloproteinases ; biosynthesis ; genetics ; Matrix Metalloproteinases, Membrane-Associated ; Middle Aged ; Neoplasm Staging ; RNA, Messenger ; biosynthesis ; genetics ; Thymoma ; classification ; enzymology ; metabolism ; pathology ; Thymus Gland ; enzymology ; metabolism ; Thymus Neoplasms ; classification ; enzymology ; metabolism ; pathology ; Tissue Inhibitor of Metalloproteinase-2 ; biosynthesis ; genetics

Breast cancer susceptibility gene, BRCA2, is a tumor suppressor and individuals who inherit one defected copy of BRCA2 allele experience early onset breast cancer or ovarian cancer accompanied by the loss of the wild type allele. Mouse model for Brca2 mutation shows growth retardation and paradoxical occurrence of thymic lymphomas. Thymic lymphomas from Brca2-mutant mice harbor mutations in p53, Bub1, and BubR1, which function as mitotic checkpoint proteins. Therefore, interplay between Brca2 and mitotic checkpoint has been suggested in the maintenance of genetic fidelity, although it has not been assessed whether the unique mutations in Bub1 and BubR1 found in Brca2-mutant mice are responsible for the abolishment of mitotic checkpoint function. This report demonstrates that Bub1 and BubR1 mutant proteins from Brca2(-/-)thymic lymphomas have defects in the phosphorylation and kinetochore localization after spindle damage. Thus, the mutations of Bub1 and BubR1 found in Brca2- mutant mice indeed are responsible for the chromosome instability in Brca2-mutated tumors.
Animals ; BRCA2 Protein/*genetics/*metabolism ; Cell Cycle Proteins ; Cell Transformation, Neoplastic/metabolism ; Mice ; *Mitosis ; Mutation/*genetics ; Phosphorylation ; Protein Kinases/*metabolism ; Protein Transport ; Support, Non-U.S. Gov't ; T-Lymphocytes/metabolism ; Thymus Neoplasms/genetics/*pathology

Carcinoma ; drug therapy ; genetics ; metabolism ; pathology ; radiotherapy ; Desmoplastic Small Round Cell Tumor ; metabolism ; pathology ; Diagnosis, Differential ; Gene Rearrangement ; Head and Neck Neoplasms ; drug therapy ; genetics ; metabolism ; radiotherapy ; Humans ; Keratin-20 ; metabolism ; Keratin-7 ; metabolism ; Lymphatic Metastasis ; Male ; Mediastinal Neoplasms ; drug therapy ; genetics ; metabolism ; radiotherapy ; Melanoma ; metabolism ; pathology ; Neuroectodermal Tumors, Primitive ; metabolism ; pathology ; Nuclear Proteins ; genetics ; metabolism ; Oncogene Proteins ; genetics ; metabolism ; Oncogene Proteins, Fusion ; genetics ; metabolism ; Rhabdomyosarcoma ; metabolism ; pathology ; Thymus Neoplasms ; drug therapy ; genetics ; metabolism ; radiotherapy

OBJECTIVETo study the clinicopathologic features of primary thymic extranodal marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT).

METHODSThe clinical and pathologic findings were evaluated in 3 cases of biopsy confirmed thymic MALT lymphoma. The clincopathologic features, treatment and prognosis were discussed and literatures reviewed.

RESULTSOne male and two female patients presented with asymptomatic mediastinal masses with a history of Sjögren syndrome. They were aged 36, 35 and 41 years respectively, and only one patient had B symptoms. Grossly, all three tumors were encapsulated and had multiple variable-sized cysts on cut-surface. Histopathologically, the normal thymic lobular architecture was effaced by abnormal dense lymphoid infiltration. Prominent lymphoepithelial lesions were formed by centrocyte-like cells infiltrating and expanding Hassall's corpuscles and epithelial cyst lining. All cases showed apparent plasmacytic differentiation. Immunohistochemically, the tumor cells were positive for CD20, CD79a, bcl-2 and negative for CD3, CD5, cyclin D1, CD43, CD10, bcl-6, and CD23. The plasma cells showed kappa light chain restriction. Immunoglobulin heavy chain rearrangement in three cases was confirmed by PCR. All patients were at early stage and received routine chemotherapy with or without radiotherapy after surgical removal. All patients achieved complete remission with 24, 18 and 3 months follow-up, respectively.

CONCLUSIONSPrimary thymic MALT lymphoma may be a rare distinctive lymphoma. It can be diagnosed by HE and immunohistochemical study and should be differentiated from reactive lymphoid proliferation, other types of lymphoma and mediastinal thymoma.

Adult ; Antibodies, Monoclonal, Murine-Derived ; therapeutic use ; Antigens, CD20 ; metabolism ; Antineoplastic Combined Chemotherapy Protocols ; therapeutic use ; Cyclophosphamide ; therapeutic use ; Diagnosis, Differential ; Doxorubicin ; therapeutic use ; Female ; Follow-Up Studies ; Gene Rearrangement, B-Lymphocyte, Heavy Chain ; Humans ; Immunoglobulin Heavy Chains ; genetics ; Keratin-19 ; metabolism ; Lymphoma, B-Cell, Marginal Zone ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Male ; Prednisone ; therapeutic use ; Pseudolymphoma ; pathology ; Thymus Hyperplasia ; pathology ; Thymus Neoplasms ; drug therapy ; genetics ; metabolism ; pathology ; surgery ; Vincristine ; therapeutic use

OBJECTIVETo observe the effect of the combination of Wenxia Changfu Formula ([see text], WCF) with cisplatin (CDDP) on inhibiting non-small cell lung cancer (NSCLC) in vitro and In Vivo and explore its mechanism from its effect on cell cycle.

METHODSIn vitro, WCF-containing serum was prepared and the rhubarb b1, emodin, and aconitine were detected qualitatively by high-performance liquid chromatogram (HPLC). A549 cell lines were treated with blank control (dimethyl sulfoxide), normal serum, normal serum with CDDP (1.25, 2.5, and 5.0 μg/mL, respectively), WCF-containing serum plus different doses of CDDP (1.25, 2.5, and 5.0 μg/mL, respectively). The inhibitory effect was detected by 3-(4,5)-dimethylthiazo(-zy1)-3,5-diphenylterazolium bromide (MTT). The cell cycle was detected by flow cytometry. The protein and mRNA expressions of cyclin D1, proliferating cell nuclear antigen (PCNA), retinoblastoma (Rb), and p16 were observed with immunofluorescence and RT-PCR, respectively. In Vivo, nude mice xenograft model was established and grouped into the control, CDDP, WCF, and combination groups. The combination's inhibition of tumor growth and influence on the weight, spleen, and thymus gland were observed.

RESULTSThe inhibitory rate of the combination against A549 cell lines excelled the CDDP alone significantly (P <0.05); the combination showed a synergism inhibitory effect (Q=1.19). Compared with the monotherapy, the combination increased the cell percentage in G(0)/G(1) phase and decreased the cell percentage in S phase significantly (P <0.05); the protein and mRNA expressions of cyclin D1, PCNA, and Rb were significantly reduced; the protein and mRNA expressions of p16 were significantly enhanced. Compared with the monotherapy, the combination inhibited the tumor growth significantly In Vivo and reduced the weight of tumor (P <0.05); compared with the CDDP group, the spleen and thymus gland index of the combination group were enhanced significantly (P <0.05).

CONCLUSIONSThe combination of WCF with CDDP significantly inhibited the A549 cell lines proliferation in vitro and the growth of the tumor In Vivo; it inhibited effectively the atrophy of the immune organ caused by chemotherapy. The combination inhibited overproliferation of A549 cell lines by arresting the G(0) /G(1) phase of cell cycle and affecting the protein and mRNA expressions of cell cycle-related proteins, cyclin D1, etc.

Animals ; Antineoplastic Agents ; pharmacology ; therapeutic use ; Antineoplastic Combined Chemotherapy Protocols ; pharmacology ; therapeutic use ; Carcinoma, Non-Small-Cell Lung ; drug therapy ; genetics ; pathology ; Cell Cycle ; drug effects ; Cell Line, Tumor ; Cell Proliferation ; drug effects ; Chromatography, High Pressure Liquid ; Cisplatin ; pharmacology ; therapeutic use ; Drug Synergism ; Drugs, Chinese Herbal ; pharmacology ; therapeutic use ; Flow Cytometry ; Gene Expression Regulation, Neoplastic ; drug effects ; Humans ; Lung Neoplasms ; drug therapy ; genetics ; pathology ; Male ; Neoplasm Proteins ; genetics ; metabolism ; RNA, Messenger ; genetics ; metabolism ; Rats ; Rats, Wistar ; Spleen ; drug effects ; pathology ; Thymus Gland ; drug effects ; pathology ; Xenograft Model Antitumor Assays