As an emerging biomarker, tumor mutational burden (TMB) has attracted increasing attention from clinicians in predicting the efficacy of tumor immunotherapy. Currently, TMB is detected primarily by whole-exome sequencing or targeted panel sequencing on high-throughput sequencing platforms. However, the lack of uniformity in detection methods, threshold settings, and reporting formats, as well as the significant differences in TMB values among different cancer types, have hindered the standardized application of this biomarker in clinical practice. This consensus focuses on the definition, standardization of detection, clinical significance, and limitations of TMB, and provides consensus recommendations for the clinical application of TMB in real-world practice in China. This consensus is aimed at helping clinicians and laboratory personnel understand the clinical significance and testing standards of TMB, promoting more accurate interpretation of test results, and improving patient care.

BACKGROUND:Pulmonary sarcomatoid carcinoma (PSC) is a highly invasive pulmonary malignancy with an extremely poor prognosis. The results of previous studies suggest that ubiquitin-specific peptidase 9X (USP9X) contributes to the progression of numerous types of cancer. Nevertheless, there is little knowledge about the molecular mechanisms and functions of USP9X in the metastasis of PSC. METHODS:Immunohistochemistry and western blotting were used to detect USP9X expression levels in PSC tissues and cells. Wound healing, transwell, enzyme-linked immunosorbent assay (ELISA), tube formation, and aortic ring assays were used to examine the function and mechanism of USP9X in the metastasis of PSC. RESULTS:Expression of USP9X was markedly decreased and significantly correlated with metastasis and prognosis of patients with PSC. Then we revealed that USP9X protein levels were negatively associated with the levels of epithelial-mesenchymal transition (EMT) markers and the migration of PSC cells. It was confirmed that USP9X in PSC cells reduced VEGF secretion and inhibited tubule formation of human umbilical vein endothelial cells (HUVEC) in vitro. USP9X was detected to downregulate MMP9. Meanwhile, MMP9 was positively related to EMT, angiogenesis and was negatively related to immune infiltration in the public databases. USP9X was significantly negatively associated with the expression of MMP9, EMT markers, CD31, and positively associated with CD4, and CD8 in PSC tissues. CONCLUSION:The present study reveals the vital role of USP9X in regulating EMT, angiogenesis and immune infiltration and inhibiting metastasis of PSC via downregulating MMP9, which provides a new effective therapeutic target for PSC.

Glioma is the most common malignant tumor of the brain and enhancing the efficacy of chemotherapy in glioma is critical for improving patients’ prognosis. In this study, a glioma-targeting drug delivery system is constructed using biodegradable periodic mesoporous organosilica nanoparticles (PMO) that are modified with lactoferrin (Lf) ligands. The obtained PMO is doped with thioether groups and can be degraded in the high concentration of glutathione in tumor cells. The surface area and pore volume of PMO are 772 cm2/g and 0.98 cm3/g, respectively and the loading capacity of doxorubicin (Dox) is as high as 20

目的 利用杆状病毒表达系统合成重组小鼠细小病毒(MVM)VP2 蛋白,并对其免疫原性分析.方法 将优化后的 MVM VP2 序列克隆至表达载体 pFastBac1,命名为 pFastBac1-MVM VP2,再将其转化至 DH10Bac 感受态大肠杆菌中形成重组杆粒,提取重组杆粒经PCR鉴定正确后转染昆虫细胞Sf9,镜下观察到细胞明显病变后收获重组杆状病毒 rBac-MVM VP2.Sf9 细胞接重组病毒 48 和 72 h 后,用间接免疫荧光(IFA)和蛋白免疫印迹(Western blot)法验证重组蛋白的免疫原性.结果 构建的 rBac-MVM VP2 重组杆状病毒感染 Sf9 细胞后,可成功表达 MVM VP2 重组蛋白,经 Western blot和 IFA检测分析,重组蛋白具有较好的免疫原性且在病毒感染 72 h 时表达量较高.经蛋白纯化后可得到纯度较高的 VP2 重组蛋白.结论 本研究利用昆虫细胞-杆状病毒系统成功表达 MVM VP2蛋白并具有良好的免疫原性,为 VP2 相关功能的研究和临床诊断方法的建立奠定基础.

目的 根据战创伤动物实验工作的实际情况,探讨其特点并提出伦理审查要点,进一步优化伦理审查体系.方法 以目前动物实验相关伦理审查实际情况为研究基础,通过综合分析战创伤动物实验的特点,提出对应的动物实验审查要点.结果 战创伤动物实验特点显著,需结合"3R原则"基础上的实验动物选择、麻醉镇痛方式审查、术后护理方式审查、实验人员操作技术审查、动物饲养管理的审查、安乐死相关伦理审查、跟踪审查频率等审查要点.结论 紧密联系实际的战创伤动物实验伦理审查可以更好地实现"3R原则",尽可能展现高效准确的实验结果,进一步明确伦理审查要点,并在未来军事医学战创伤研究中推广应用.

Supplementary Figure 8 - The effects of storage duration (baseline vs. 6 months) on the circulation level of miR-16 in plasma of cases and controls, separately.

Breast cancer is one of the leading cancer forms affecting females worldwide. Characterizing the mechanical properties of breast cancer tissue is important for diagnosis and uncovering the mechanobiology mechanism. Although most of the studies were based on human cancer tissue, an animal model is still describable for preclinical analysis. Using a custom-build indentation device, we measured the viscoelastic properties of breast cancer tissue from 4T1 and SKBR3 cell lines. A total of 7 samples were tested for each cancer tissue using a mouse model. We observed that a viscoelastic model with 2-term Prony series could best describe the ramp and stress relaxation of the tissue. For long-term responses, the SKBR3 tissues were stiffer in the strain levels of 4–10%, while no significant differences were found for the instantaneous elastic modulus. We also found tissues from both cell lines appeared to be strain-independent for the instantaneous elastic modulus and for the long-term elastic modulus in the strain level of 4–10%. In addition, by inspecting the cellular morphological structure of the two tissues, we found that SKBR3 tissues had a larger volume ratio of nuclei and a smaller volume ratio of extracellular matrix (ECM). Compared with prior cellular mechanics studies, our results indicated that ECM could contribute to the stiffening the tissue-level behavior. The viscoelastic characterization of the breast cancer tissue contributed to the scarce animal model data and provided support for the linear viscoelastic model used for in vivo elastography studies. Results also supplied helpful information for modeling of the breast cancer tissue in the tissue and cellular levels.

During development, neural crest (NC) cells are induced by signaling events at the neural plate border of all vertebrate embryos. Initially arising within the central nervous system, NC cells subsequently undergo an epithelial to mesenchymal transition to migrate into the periphery, where they differentiate into diverse cell types. Here we provide evidence that postnatal human epidermal keratinocytes (KC), in response to fibroblast growth factor 2 and insulin like growth factor 1 signals, can be reprogrammed toward a NC fate. Genome-wide transcriptome analyses show that keratinocyte-derived NC cells are similar to those derived from human embryonic stem cells. Moreover, they give rise in vitro and in vivo to NC derivatives such as peripheral neurons, melanocytes, Schwann cells and mesenchymal cells (osteocytes, chondrocytes, adipocytes, and smooth muscle cells). By demonstrating that human keratin-14+ KC can form NC cells, even from clones of single cells, our results have important implications in stem cell biology and regenerative medicine. Stem Cells 2017;35:1402-1415.

The incidence rate of hepatocellular carcinoma (HCC) is higher in populations of Asian ancestry than European ancestry (EA). We sought to investigate HCC mutational differences between the two populations, which may reflect differences in the prevalence of etiological factors. We compared HCC somatic mutations in patients of self-reported Asian American and EA from The Cancer Genome Atlas (TCGA), and assessed associations of tumor mutations with established HCC risk factors. Although the average mutation burden was similar, TP53 and RB1 were mutated at a much higher frequency in Asian Americans than in EAs (TP53: 43% vs. 21%; RB1: 19% vs. 2%). Three putative oncogenic genes, including TRPM3, SAGE1, and ADAMTS7, were mutated exclusively in Asians. In addition, VEGF binding pathway, a druggable target by tyrosine kinase inhibitors such as sorafenib, was mutated at a higher frequency among Asians (13% vs. 2%); while the negative regulation of IL17 production, involved in inflammation and autoimmunity, was mutated only in EAs (12% vs. 0). Accounting for HCC risk factors had little impact on any of the mutational differences. In conclusion, we demonstrated here mutational differences in important cancer genes and pathways between Asian and European ancestries. These differences may have implications for the prevention and treatment of HCC.

The genetic landscape and molecular features of collecting duct carcinoma (CDC) of the kidney remain largely unknown. Herein, we performed whole exome sequencing (WES) and transcriptome sequencing (RNASeq) on 7 CDC samples (CDC1 -7). Among the 7 samples, 4 samples with matched non-tumor tissue were used for copy number analysis by SNP array data. No recurrent somatic SNVs were observed except for MLL, which was found to be mutated (p.V297I and p.F407C) in 2 samples. We identified somatic SNVs in 14 other cancer census genes including: ATM, CREBBP, PRDM1, CBFB, FBXW7, IKZF1, KDR, KRAS, NACA, NF2, NUP98, SS18, TP53, and ZNF521. SNP array data identified a CDKN2A homozygous deletion in 3 samples and SNV analysis showed a non-sense mutation of the CDKN2A gene with unknown somatic status. To estimate the recurrent rate of CDKN2A abnormalities, we performed FISH screening of additional samples and confirmed the frequent loss (62.5%) of CDKN2A expression. Since cisplatin based therapy is the common treatment option for CDC, we investigated the expression of solute carrier (SLC) family transporters and found 45% alteration. In addition, SLC7A11 (cystine transporter, xCT), a cisplatin resistance associated gene, was found to be overexpressed in 4 out of 5 (80%) cases of CDC tumors tested, as compared to matched non-tumor tissue. In summary, our study provides a comprehensive genomic analysis of CDC and identifies potential pathways suitable for targeted therapies.

目的：探讨TdT阴性的T淋巴母细胞淋巴瘤的临床病理学特征、诊断、鉴别诊断及预后。方法对1例TdT阴性的T淋巴母细胞淋巴瘤进行临床病理学观察,并复习相关文献。结果患者男性,25岁,胸部CT示胸腺侵袭性占位伴左上纵隔淋巴结增大。镜检：肿瘤细胞弥漫分布,瘤细胞圆形,小至中等大小,胞质少,核深染,圆形、卵圆形或不规则,核分裂象易见,脂肪组织内有肿瘤细胞累及。免疫表型：肿瘤细胞弥漫一致性表达 CD99、CD34和 CD43,不表达 TdT、MPO、CD117、CD1a、CD2、CD3、CD4和CD8等。基因重排检测结果显示存在IGH-B和TCRD基因重排。结论 TdT阴性的T淋巴母细胞淋巴瘤是一种罕见的高度恶性肿瘤,其诊断与鉴别诊断主要依赖于病理学形态、免疫表型和分子病理学检测。

Granular cell tumors are an uncommon soft tissue neoplasm. Malignant granular cell tumors comprise <2% of all granular cell tumors, are associated with aggressive behavior and poor clinical outcome, and are poorly understood in terms of tumor etiology and systematic treatment. Because of its rarity, the genetic basis of malignant granular cell tumor remains unknown. We performed whole-genome sequencing of one malignant granular cell tumor with metabolic response to pazopanib. This tumor exhibited a very low mutation rate and an overall stable genome with local complex rearrangements. The mutation signature was dominated by C>T transitions, particularly when immediately preceded by a 5' G. A loss-of-function mutation was detected in a newly recognized tumor suppressor candidate, BRD7. No mutations were found in known targets of pazopanib. However, we identified a receptor tyrosine kinase pathway mutation in GFRA2 that warrants further evaluation. To the best of our knowledge, this is only the second reported case of a malignant granular cell tumor exhibiting a response to pazopanib, and the first whole-genome sequencing of this uncommon tumor type. The findings provide insight into the genetic basis of malignant granular cell tumors and identify potential targets for further investigation.

Somatic Structural Variations (SVs) are a complex collection of chromosomal mutations that could directly contribute to carcinogenesis. Next Generation Sequencing (NGS) technology has emerged as the primary means of interrogating the SVs of the cancer genome in recent investigations. Sophisticated computational methods are required to accurately identify the SV events and delineate their breakpoints from the massive amounts of reads generated by a NGS experiment. In this review, we provide an overview of current analytic tools used for SV detection in NGS-based cancer studies. We summarize the features of common SV groups and the primary types of NGS signatures that can be used in SV detection methods. We discuss the principles and key similarities and differences of existing computational programs and comment on unresolved issues related to this research field. The aim of this article is to provide a practical guide of relevant concepts, computational methods, software tools and important factors for analyzing and interpreting NGS data for the detection of SVs in the cancer genome.

Background The molecular biology and cellular origins of mixed type endometrial carcinomas (MT-ECs) are poorly understood, and a Type II component of 10 percent or less may confer poorer prognoses. Methodology/Principal Findings We studied 10 cases of MT-EC (containing endometrioid and serous differentiation), 5 pure low-grade endometrioid adenocarcinoma (EAC) and 5 pure uterine serous carcinoma (USC). Endometrioid and serous components of the MT-ECs were macrodissected and the expression of 60 candidate genes compared between MT-EC, pure USC and pure EAC. We found that four genes were differentially expressed when MT-ECs were compared to pure low-grade EAC: CDKN2A (P = 0.006), H19 (P = 0.010), HOMER2 (P = 0.009) and TNNT1 (P = 0.006). Also while we found that even though MT-ECs closely resembled the molecular profiles of pure USCs, they also exhibit lower expression of PAX8 compared to all pure cases combined (P = 0.035). Conclusion Our data suggest that MT-EC exhibits the closest molecular and epidemiological similarities to pure USC and supports clinical observations that suggest patients with MT-EC should receive the same treatment as patients with pure serous carcinoma. Novel specific markers of MT-EC could be of diagnostic utility and could represent novel therapeutic targets in the future.

Purpose To explore the immunohistochemical ( IHC) expression of ALK antibodies with different clones in anaplastic lym-phoma kinase ( ALK) gene fusion non-small cell lung cancer ( NSCLC) . Methods ALK expression in 60 NSCLCs were detected by IHC including autostainer (D5F3, Ventana+BenchMark) and manual staining using 4 different antibodies of D5F3 (Ventana), D5F3 (Cell Signaling), 1A4/1H7 (OriGene), 5A4 (Abcam), and all cases were verified with ALK FISH. Their expressions with 4 anti-bodies were compared with those by D5F3 (Ventana+BenchMark). Results 32 ALK gene rearrangement NSCLCs and 28 negative cases were identified by FISH and D5F3 (Ventana+BenchMark). The sensitivity of D5F3 (Ventana), D5F3 (Cell Signaling), 1A4/1H7 (OriGene), 5A4 (Abcam) was 93. 8%, 84. 4%, 93. 8%, 56. 3%, and all the speciticity was 100%. The consistency with D5F3 (Ventana+BenchMark) was 96. 7%, 91. 7%, 96. 7% and 76. 7%, respectively. The validity of immunohistochemical staining in surgical resection specimens was better than in small biopsies. Conclusion Effective routine manual immunohistochemistry with high-affinity antibody clone may provide a more economic and widespread pre-screening technique.

OBJECTIVE:To explore the automated immunostainer screening anaplastic lymphoma kinase (ALK) gene fusion non-small cell lung cancer (NSCLC) and clinicopathological characteristics of the molecular subtype lung cancers. Methods Five hundred and sixty-six cases of NSCLC were collected over a 16 month period. The test for ALK was performed by Ventana automated immunostainer with anti-ALK D5F3. The histological features, treatment and outcome of patients were assessed. Results Thirty-eight cases (6.7%, 38/566) of NSCLC showed ALK gene fusion. The frequency of ALK gene fusion was higher in male (7.1%, 25/350) than that in female (6.0%, 13/216) patients, but not achieving statistical significance (chi2 = 0.270, P = 0.604). ALK + NSCLC was more significantly more frequent in patients < or = 60 years (9.9%, 28/282) than >60 years (3.5% , 10/284) of age. Histologically, the ALK + NSCLCs were mostly adenocarcinoma (81.6%, 31/38) , among which eighteen cases were solid predominant subtype with mucin production; nine cases were acinar predominant subtype; one case was papillary predominant subtype and three cases were invasive mucinous adenocarcinoma. The ALK + non-adenocarcinoma included three cases of squamous cell carcinoma, three cases of adenosquamous carcinoma and one case of pleomorphic carcinoma. Among the ALK + NSCLC patients, the number of non/light cigarette smokers (86. 8% , 33/38) was more than that of heavy smokers. Twenty-nine cases were stages III and IV; twenty-nine cases showed lymph node metastasis; twenty cases showed metastases mostly to brain and bone; and one case showed EGFR gene mutation coexisting with ALK gene fusion. Twelve of fifteen patients received crizotinib therapy and remained stable. Conclusions NSCLC with ALK gene rearrangement shows distinctive clinical and histological features. Ventana-IHC may he a feasible and valid technique for detection of ALK rearrangement in NSCLC.

Abstract Collecting duct renal cell carcinoma (CDC) is a rare (∼1-3%) type of kidney cancer, aggressive in nature, associated with poor prognosis and limited response to treatments such as cisplatin/gemcitabine and tyrosine kinase inhibitors. Accordingly, there is an unmet need for understanding the molecular alterations associated with CDC and the development of novel effective therapeutic agents for this disease. Since cisplatin based therapy is widely used to manage CDC and the response is often very limited, we investigated the possible molecular alteration(s) associated with cisplatin resistance in CDC. RNA sequence analysis was performed on 5 CDC cases to evaluate gene expression profiles. Immunohistochemical analysis was performed on 6 cases of CDC tumor samples (2 cases included in sequencing) and their matched normal kidneys arranged in a tissue microarray to assess the representative overexpressed genes. Clinical annotation was evaluated to determine the association of gene expression with cisplatin based therapy response and survival. RNA sequencing analysis data revealed the upregulation of 2879 genes and the downregulation of 1951 genes in CDC tumors, as compared to matched normals. Among the altered genes, many of them were transporters. Since transporters play a significant role in drug resistance mechanism(s), particularly in cisplatin resistance, we investigated the Solute Carrier (SLC) family group of membrane transporter genes and found 41 genes upregulated (log2 fold change of 6.4 to 1.0) and 95 genes downregulated (log2 fold change of -8.4 to -0.8). The number of altered SLC family genes was 136 (41 upregulated and 95 downregulated), which is 3.8 percent (136 out of 4830) of the total gene alterations and 45.3% (136 out of 300) of the SLC group of family members, indicating their significance in CDC. The critical analysis of individual amino acid transporters of SLC family genes from the upregulated group led us to investigate three transporters: SLC7A11 (xCT, cystine transporter), SLC1A3 (GLAST, glutamate and aspartate transporter), and SLC6A7 (PROT, proline transporter), which are known to be drug resistance markers. RNA sequence data showed the upregulation of SLC7A11 and SLC1A3 mRNA in 75% of the cases (3 out of 4), with SLC6A7 upregulated in 100% of the cases (4 out of 4). Immunohistochemical analysis of 6 CDC tumors revealed the overexpression of xCT, a known marker for cisplatin resistance in 66% (4 out of 6) of the cases. Kaplan Meyer survival analysis revealed the worst survival for CDC patients with xCT overexpression. Our results demonstrate for the first time that overexpression of xCT, a known cisplatin resistance marker, is associated with CDC. These results suggest that xCT targeted combination therapies may be beneficial to CDC patients. Citation Format: Sreenivasulu Chintala, Jianmin Wang, Lei Wei, Biao Liu, Eric Ciamporcero, Kiersten Marie Miles, May Elbanna, Remi Adelaiye, Li Shen, Ashley Orillion, Sheng Yu Ku, Antonios Papanicolau-Sengos, Carl D. Morrison, Roberto Pili. Solute carrier family group of membrane transporter gene alteration in collecting duct renal cell carcinoma. [abstract]. In: Proceedings of the 106th Annual Meeting of the American Association for Cancer Research; 2015 Apr 18-22; Philadelphia, PA. Philadelphia (PA): AACR; Cancer Res 2015;75(15 Suppl):Abstract nr 4300. doi:10.1158/1538-7445.AM2015-4300

Objectives: Anaplastic lymphoma kinase (ALK-rearranged non-small cell lung cancer (NSCLC) screening is essential to its treatment such as crizotinib. Different assays have been developed to detect ALK rearrangements, such as fluorescence in situ hybridization (FISH), reverse transcriptase-PCR (RT-PCR), and immunohistochemistiy (IHC). However, ALK detection has not been applied widely in all hospitals. Moreover, IHC has been proposed to be a pre-screening tool because of its wide application in clinics. Since the low expression of ALK protein, the sensitivity and specificity of ALK antibody are the keys to the success of IHC screening. Therefore, we compared different antibodies to find the best one for IHC detection.Materials and methods: We evaluated ALK expression by four different ALK antibodies: clone D5F3 (Ventana), clone D5F3 (CST), clone 1A4/1H7 (OriGene Tech.), and clone 5A4 (Abcam) based on manual IHC in a cohort of 60 NSCLCs. The results were compared with those from automated IHC (clone D5F3, Ventana). All cases were evaluated independently by ALK FISH.Results: 32 ALK-positive and 28 ALK-negative NSCLCs were identified by automated IHC (D5F3, Ventana) and FISH analysis. Based on conventional manual IHC, the sensitivity of four antibodies D5F3 (Ventana), D5F3 (CST), 1A4/1 H7 (OriGene Tech.), and 5A4 (Abcam) was 93.8%, 84.4%, 93.8%, and 56.3%, respectively. Their specificities and positive predictive values were 100%. The percentage of strong-moderate staining was 65.6%, 62.5%, 68.8%, and 21.9%, respectively. Compared with automated IHC (D5F3, Ventana), each staining concordance was 96.7%, 91.7%, 96.7%, and 77%, respectively, and each presented staining heterogeneity (weak-moderate-strong intensity).Conclusion: These data indicated that manual IHC with a more reliable ALK antibody might provide an effective strategy for screening ALK gene rearrangements in all NSCLC patients, followed by confirmatory FISH analysis in IHC-positive cases. (c) 2015 Elsevier Ireland Ltd. All rights reserved.

An increasing number of TFE3 rearrangement-associated tumors, such as TFE3 rearrangement-associated perivascular epithelioid cell tumors (PEComas), melanotic Xp11 translocation renal cancers, and melanotic Xp11 neoplasms, have recently been reported. We examined 12 such cases, including 5 TFE3 rearrangement-associated PEComas located in the pancreas, cervix, or pelvis and 7 melanotic Xp11 translocation renal cancers, using clinicopathologic, immunohistochemical, and molecular analyses. All the tumors shared a similar morphology, including a purely nested or sheet-like architecture separated by a delicate vascular network, purely epithelioid cells displaying a clear or granular eosinophilic cytoplasm, a lack of papillary structures and spindle cell or fat components, uniform round or oval nuclei containing small visible nucleoli, and, in most cases (11/12), melanin pigmentation. The levels of mitotic activity and necrosis varied. All 12 cases displayed moderately (2+) or strongly (3+) positive immunoreactivity for TFE3 and cathepsin K. One case labeled focally for HMB45 and Melan-A, whereas the others typically labeled moderately (2+) or strongly (3+) for 1 of these markers. None of the cases were immunoreactive for smooth muscle actin, desmin, CKpan, S100, or PAX8. PSF-TFE3 fusion genes were confirmed by reverse transcription polymerase chain reaction in cases (7/7) in which a novel PSF-TFE3 fusion point was identified. All of the cases displayed TFE3 rearrangement associated with Xp11 translocation. Furthermore, we developed a PSF-TFE3 fusion fluorescence in situ hybridization assay for the detection of the PSF-TFE3 fusion gene and detected it in all 12 cases. Clinical follow-up data were available for 7 patients. Three patients died, and 2 patients (cases 1 and 3) remained alive with no evidence of disease after initial resection. Case 2 experienced recurrence and remained alive with disease. Case 5, a recent case, remained alive with extensive abdominal cavity metastases. Our data suggest that these tumors belong to a single clinicopathologic spectrum and expand the known characteristics of TFE3 rearrangement-associated tumors.

AimsMalignant rhabdoid tumours (MRTs) are highly aggressive malignancies of early infancy characterized by inactivation of SMARCB1, a core member of the SWI/SNF chromatin-remodelling complex. The aim of this study was to explore the status of multiple key subunits of the SWI/SNF complex in MRTs.Methods and resultsWe screened the key subunits of the SWI/SNF complex, including SMARCB1, SMARCA2, PBRM1, SMARCA4, and ARID1A, in four MRTs by immunohistochemistry, sequencing, and fluorescence in-situ hybridization (FISH). Complete loss of SMARCB1, SMARCA2 and PBRM1 expression and corresponding mutations in the same genes were observed in all cases. The mutations included seven missense, three same-sense, four frameshift and two truncating mutations. FISH revealed heterozygous deletion of SMARCB1 in one case, and monoploidy of chromosome 22, which harbours SMARCB1, in another case. Furthermore, trisomy of chromosome 9, which harbours SMARCA2, was observed in two cases. Abnormality of PBRM1 was not found in any case.ConclusionsWe report, for the first time, co-inactivation and frequent mutations of SMARCB1, SMARCA2 and PBRM1 in MRTs. Multiple subunit abnormalities of the SWI/SNF complex potentially act together to contribute to the tumorigenesis of MRTs, which provides unique insights into this disease.