A Novel CASC15-ALK and TFG-ROS1 Fusion Observed in Uterine Inflammatory Myofibroblastic Tumor.

The majority of inflammatory myofibroblastic tumors (IMTs) in the gynecologic tract occur in the uterine corpus and harbor anaplastic lymphoma kinase ( ALK ) rearrangement. Herein, we report 1 uterine IMT case with a novel fusion involving ALK and 1 uterine IMT case with ROS1 rearrangement. The ages of the patients were 56 and 57 yr, respectively. The tumor size was 10.0 and 8.0 cm, respectively. Both patients had stage IB disease. Histologically, the 2 IMT cases had classic morphologic features and predominantly comprised bland spindle cells with hypercellular (fascicular/storiform) and hypocellular (myxoid rich) areas admixed with variably prominent lymphoplasmacytic infiltration. Immunohistochemically, the ALK -rearranged case was positive for ALK , and the ROS1 -rearranged case was positive for ROS1 . Both cases were diffusely positive for desmin. The tumor cells were variably positive for estrogen receptor (1/2 cases, 50.0%) and progesterone receptor (1/2 cases, 50.0%). Targeted RNA sequencing revealed one case each with either a novel CASC15-ALK or TFG-ROS 1 fusion. We identified a novel ALK fusion partner CASC15 in IMT and described the first uterine IMT with a TFG-ROS1 fusion. This study improves our understanding of molecular events in IMT.

A NOTCH1 Mutation Found in a Newly Established Ovarian Cancer Cell Line (FDOVL) Promotes Lymph Node Metastasis in Ovarian Cancer.

Peritoneal implantation and lymph node metastasis have different driving mechanisms in ovarian cancer. Elucidating the underlying mechanism of lymph node metastasis is important for treatment outcomes. A new cell line, FDOVL, was established from a metastatic lymph node of a patient with primary platinum-resistant ovarian cancer and was then characterized. The effect of NOTCH1-p.C702fs mutation and NOTCH1 inhibitor on migration was evaluated in vitro and in vivo. Ten paired primary sites and metastatic lymph nodes were analyzed by RNA sequencing. The FDOVL cell line with serious karyotype abnormalities could be stably passaged and could be used to generated xenografts. NOTCH1-p.C702fs mutation was found exclusively in the FDOVL cell line and the metastatic lymph node. The mutation promoted migration and invasion in cell and animal models, and these effects were markedly repressed by the NOTCH inhibitor LY3039478. RNA sequencing confirmed CSF3 as the downstream effector of NOTCH1 mutation. Furthermore, the mutation was significantly more common in metastatic lymph nodes than in other peritoneal metastases in 10 paired samples (60% vs. 20%). The study revealed that NOTCH1 mutation is probably a driver of lymph node metastasis in ovarian cancer, which offers new ideas for the treatment of ovarian cancer lymph node metastasis with NOTCH inhibitors.

Uterine tumours with myogenic differentiation harbouring SRF::RELA fusions.

AIMS: In 2017, a subset of cellular variants of myofibroma and myopericytoma with a smooth muscle-like immunophenotype and harbouring recurrent SRF::RELA gene fusions was reported. Although the anatomical distribution was found to be quite broad, no tumours with these gene fusions in the female reproductive system have been illustrated to date. METHODS AND RESULTS: Herein, we report the histological and immunophenotypical features of three uterine tumours with SRF::RELA gene fusions. Microscopically, all three tumours were composed of cellular oval to spindle cells arranged in intersecting fascicles with variable amounts of collagen and a rich capillary network. Mitotic figures were scant. Regarding immunohistochemistry, diffuse staining for desmin, oestrogen receptor and progesterone receptor was observed in all three cases. The first case exhibited focal staining for h-caldesmon, whereas the latter two cases had diffuse staining. Furthermore, SRF::RELA rearrangement was observed in all three cases by using next-generation sequencing (NGS). Follow-up, ranging from 11 to 15 months, was available for these three patients, all of whom were well without evidence of disease. CONCLUSIONS: In conclusion, we reported a special group of uterine neoplasms with myogenic differentiation harbouring SRF::RELA rearrangement. Although the follow-up time was limited, morphological characteristics and other studies with follow-up data supported that this type of uterine neoplasm appeared to behave in a benign manner. Further studies with longer follow-up are needed to clarify the biological nature of this particular type of uterine tumour.

Concordance of the 21-gene assay between core needle biopsy and resection specimens in early breast cancer patients.

BACKGROUND: Adjuvant therapy decisions may be partly based on the results of a multigene quantitative reverse transcription-polymerase chain reaction (RT-PCR)-based assay: the 21-gene recurrence score (RS) test of resection specimens. When necessary, core needle biopsy (CNB) may be considered as a surrogate. Here, we evaluated the concordance in gene expression according to results from RT-PCR-based RS testing between paired CNBs and resection specimens. METHODS: CNBs and resection specimens from 50 breast cancer (BC) patients were tested to calculate RSs. First, we examined the concordance of the ER, PR and HER-2 status of tissue samples indicated by immunohistochemical (IHC) and RT-PCR analyses. Then, we compared the IHC findings of ER, PR, HER-2 and Ki-67 staining across paired samples. Ultimately, the RS and single-gene results for ER, PR, HER-2 and Ki-67 were explored between paired samples. RESULTS: The concordance between IHC and RT-PCR was 100%, 80.0% and 100% for ER, PR and HER-2, respectively, in both resection specimens and CNBs. The concordance for IHC ER, PR, HER-2 and Ki-67 status was 100%, 94.0%, 52.0% and 82.0%, respectively, between paired samples. RS results from paired samples showed a strong correlation. The overall concordance in RS group classification between samples was 74%, 72% and 78% based on traditional cutoffs, TAILORx cutoffs and ASCO guidelines, respectively. ER, PR, HER-2 and Ki-67 were modestly- to- strongly correlated between paired samples according to the RT-PCR results. CONCLUSION: A modest- to- strong correlation of ER, PR, HER-2 and Ki-67 gene expression and RS between CNBs and resection specimens was observed in the present study. The 21-gene RS test could be reliably performed on CNBs. ER, PR and HER-2 status showed remarkable concordance between the IHC and RT-PCR analyses. The concordance between paired samples was high for the IHC ER, PR and Ki-67 results and low for HER-2.

Immunohistochemistry-Based Consensus Molecular Subtypes as a Prognostic and Predictive Biomarker for Adjuvant Chemotherapy in Patients with Stage II Colorectal Cancer.

BACKGROUND: For stage II colorectal cancer (CRC), the efficacy of adjuvant chemotherapy remains controversial. Consensus molecular subtype (CMS) has been validated to be a prognostic tool for CRCs. In this study, CMS status was investigated as a prognostic biomarker for the efficacy of adjuvant chemotherapy for stage II colorectal cancer. MATERIALS AND METHODS: The tissue microarray was retrospectively constructed of 165 nonconsecutive, primary, and sporadic stage II CRCs. CMS status was determined by immunohistochemistry staining of CDX2, HTR2B, FRMD6, and ZEB1, combining with microsatellite instability testing. The prognostic for adjuvant chemotherapy efficacy of CMS status was calculated by Kaplan-Meier curves and Cox regression analysis. Subgroup analyses were conducted according to tumor location. RESULTS: Kaplan-Meier curves indicated that CMS was associated with overall survival (OS) and disease-free survival for stage II CRCs. Cox regression analysis showed that CMS was an independent risk factor for OS. Among high-risk clinicopathological factors, patients with CMS2/3 (hazard ratio [HR]: 0.445, 95% confidence interval [CI]: 0.227-0.875), left-sided tumors (HR: 0.488, 95% CI: 0.247-0.968), or fewer than 12 lymph nodes examined (HR: 0.307, 95% CI: 0.097-0.974) had survival benefit from adjuvant chemotherapy. Subgroup analysis showed that adjuvant chemotherapy only improved OS for patients with left-sided tumors of CMS2/3 subtype. Regardless of CMS, right-sided tumors had no benefit from adjuvant chemotherapy. CONCLUSION: CMS is a better prognostic factor for adjuvant chemotherapy for stage II CRCs. Together with tumor location, CMS classification will aid in personalized treatment for stage II CRCs. IMPLICATIONS FOR PRACTICE: For stage II colorectal cancer (CRC), the efficacy of adjuvant chemotherapy remains controversial, in that its minimal benefit (no more than 5% on average) is considered not worth the toxic effects of the drugs. There are still no effective prognostic and predictive biomarkers. This study showed that consensus molecular subtype (CMS) status is a predictive marker for adjuvant chemotherapy efficacy. Patients with left-sided tumors of CMS2/3 subtype have survival benefit by receiving adjuvant chemotherapy, which will aid in personalized treatment for stage II CRCs. Moreover, this test of CMS based on immunohistochemistry is cheap, not time consuming, and easily conducted in the laboratories of most hospitals.

Invasive apocrine carcinoma of the breast: clinicopathologic features and comprehensive genomic profiling of 18 pure triple-negative apocrine carcinomas.

Pure invasive apocrine carcinoma is a rare type of primary breast cancer, constituting ~1% of all breast cancers. Since most pure invasive apocrine carcinomas are triple negative, the lack of targeted therapies for triple-negative breast cancer has fostered efforts to discover actionable molecular targets in these tumors. In this study, we analyzed the clinicopathologic characteristics and comprehensive genomic profiling of 18 patients with pure triple-negative apocrine carcinomas (TNACs) using a 324-gene panel assay (FoundationOne CDx). The median age of these patients was 55.5 years, and the postmenopausal status rate was 77.8%. In total, 83.3% of patients were diagnosed with histological grade II, and 16.7% were diagnosed with grade III. The majority of patients presented at an early tumor-node-metastasis (TNM) stage (I: 38.9%; II: 50.0%; and III: 11.1%). The mean Ki-67 index was 9.7%, and the percent of PD-L1 positivity was 11.7%. With a median follow-up period of 76.5 months, one patient died, and two experienced distant metastases. There were 61 clinically relevant genomic alterations among all 18 pure TNACs, and the mean tumor mutation burden (TMB) was 3 Mut/Mb. The top ranked altered genes were PIK3CA (72.2%), PTEN (33.3%) and TP53 (27.8%). There were four novel mutations found in PTEN and an actionable rearrangement involving FGFR2-TACC2 that has not been reported in breast cancer before. In total, 88.9%, 50%, 44.4%, and 16.7% of TNACs had at least one clinically relevant genomic alteration in genes involved in the PI3K/mTOR, cell cycle, RAS/RAF/MEK and growth factor receptor-related pathways, respectively. All patients had at least one clinically relevant genomic alteration, and 94.4% had at least one actionable alteration. To the best of our knowledge, this study is the largest genomic sequencing cohort of pure TNACs. Incorporation of comprehensive genomic profiling into TNACs might shed light on potential therapeutic opportunities for both targeted drugs and immune checkpoint inhibitors.

Systematic identification of rabbit LncRNAs reveals functional roles in atherosclerosis.

Long noncoding RNAs (lncRNAs) have been gradually emerging as important regulators in various biological processes and diseases, while the contributions of lncRNAs to atherosclerosis remain largely unknown. Our previous work has discovered atherosclerosis associated protein-coding genes by transcriptome sequencing of rabbit models. Here we investigated the roles of lncRNAs in atherosclerosis. We defined a stringent set of 3736 multi-exonic lncRNA transcripts in rabbits. All lncRNAs are firstly reported and 609 (16.3%) of them are conserved in 13 species. Rabbit lncRNAs have similar characteristics to lncRNAs in other mammals, such as relatively short length, low expression, and highly tissue-specificity. The integrative analysis of lncRNAs and co-expressed genes characterize diverse functions of lncRNAs. Comparing two kinds of atherosclerosis models (LDLR-deficient WHHL rabbits and cholesterol-fed NZW rabbits) with their corresponding controls, we found the expression changes of two rabbit models were similar in aorta in but different in liver. The shared change in aorta revealed a subset of lncRNAs involved in immune response, while the cholesterol-fed NZW rabbits showed broader lncRNA expression changes in skeletal muscle system compared to WHHL rabbits. These atherosclerosis-associated lncRNAs and genes provide hits for the experimental validation of lncRNA functions. In summary, our study systematically identified rabbit lncRNAs for the first time and provides new insights for understanding the functions of lncRNAs in atherosclerosis. This article is part of a Special Issue entitled: Accelerating Precision Medicine through Genetic and Genomic Big Data Analysis edited by Yudong Cai & Tao Huang.

PDXliver: a database of liver cancer patient derived xenograft mouse models.

BACKGROUND: Liver cancer is the second leading cause of cancer-related deaths and characterized by heterogeneity and drug resistance. Patient-derived xenograft (PDX) models have been widely used in cancer research because they reproduce the characteristics of original tumors. However, the current studies of liver cancer PDX mice are scattered and the number of available PDX models are too small to represent the heterogeneity of liver cancer patients. To improve this situation and to complement available PDX models related resources, here we constructed a comprehensive database, PDXliver, to integrate and analyze liver cancer PDX models. DESCRIPTION: Currently, PDXliver contains 116 PDX models from Chinese liver cancer patients, 51 of them were established by the in-house PDX platform and others were curated from the public literatures. These models are annotated with complete information, including clinical characteristics of patients, genome-wide expression profiles, germline variations, somatic mutations and copy number alterations. Analysis of expression subtypes and mutated genes show that PDXliver represents the diversity of human patients. Another feature of PDXliver is storing drug response data of PDX mice, which makes it possible to explore the association between molecular profiles and drug sensitivity. All data can be accessed via the Browse and Search pages. Additionally, two tools are provided to interactively visualize the omics data of selected PDXs or to compare two groups of PDXs. CONCLUSION: As far as we known, PDXliver is the first public database of liver cancer PDX models. We hope that this comprehensive resource will accelerate the utility of PDX models and facilitate liver cancer research. The PDXliver database is freely available online at: http://www.picb.ac.cn/PDXliver/.

Subpathway-GM: identification of metabolic subpathways via joint power of interesting genes and metabolites and their topologies within pathways.

Various 'omics' technologies, including microarrays and gas chromatography mass spectrometry, can be used to identify hundreds of interesting genes, proteins and metabolites, such as differential genes, proteins and metabolites associated with diseases. Identifying metabolic pathways has become an invaluable aid to understanding the genes and metabolites associated with studying conditions. However, the classical methods used to identify pathways fail to accurately consider joint power of interesting gene/metabolite and the key regions impacted by them within metabolic pathways. In this study, we propose a powerful analytical method referred to as Subpathway-GM for the identification of metabolic subpathways. This provides a more accurate level of pathway analysis by integrating information from genes and metabolites, and their positions and cascade regions within the given pathway. We analyzed two colorectal cancer and one metastatic prostate cancer data sets and demonstrated that Subpathway-GM was able to identify disease-relevant subpathways whose corresponding entire pathways might be ignored using classical entire pathway identification methods. Further analysis indicated that the power of a joint genes/metabolites and subpathway strategy based on their topologies may play a key role in reliably recalling disease-relevant subpathways and finding novel subpathways.

Topologically inferring risk-active pathways toward precise cancer classification by directed random walk.

MOTIVATION: The accurate prediction of disease status is a central challenge in clinical cancer research. Microarray-based gene biomarkers have been identified to predict outcome and outperform traditional clinical parameters. However, the robustness of the individual gene biomarkers is questioned because of their little reproducibility between different cohorts of patients. Substantial progress in treatment requires advances in methods to identify robust biomarkers. Several methods incorporating pathway information have been proposed to identify robust pathway markers and build classifiers at the level of functional categories rather than of individual genes. However, current methods consider the pathways as simple gene sets but ignore the pathway topological information, which is essential to infer a more robust pathway activity. RESULTS: Here, we propose a directed random walk (DRW)-based method to infer the pathway activity. DRW evaluates the topological importance of each gene by capturing the structure information embedded in the directed pathway network. The strategy of weighting genes by their topological importance greatly improved the reproducibility of pathway activities. Experiments on 18 cancer datasets showed that the proposed method yielded a more accurate and robust overall performance compared with several existing gene-based and pathway-based classification methods. The resulting risk-active pathways are more reliable in guiding therapeutic selection and the development of pathway-specific therapeutic strategies. AVAILABILITY: DRW is freely available at http://210.46.85.180:8080/DRWPClass/

The detection of risk pathways, regulated by miRNAs, via the integration of sample-matched miRNA-mRNA profiles and pathway structure.

The use of genome-wide, sample-matched miRNA (miRNAs)-mRNA expression data provides a powerful tool for the investigation of miRNAs and genes involved in diseases. The identification of miRNA-regulated pathways has been crucial for analysis of the role of miRNAs. However, the classical identification method fails to consider the structural information of pathways and the regulation of miRNAs simultaneously. We proposed a method that simultaneously integrated the change in gene expression and structural information in order to identify pathways. Our method used fold changes in miRNAs and gene products, along with the quantification of the regulatory effect on target genes, to measure the change in gene expression. Topological characteristics were investigated to measure the influence of gene products on entire pathways. Through the analysis of multiple myeloma and prostate cancer expression data, our method was proven to be effective and reliable in identifying disease risk pathways that are regulated by miRNAs. Further analysis showed that the structure of a pathway plays a crucial role in the recognition of the pathway as a factor in disease risk.

Evaluation of the Idylla™ EGFR Mutation Test on formalin-fixed, paraffin-embedded tissue of human lung cancer.

Background: Epidermal growth factor receptor (EGFR) mutation detection is essential for the therapy of lung cancer. A sensitive, specific, and cost-effective standardized method to quickly and accurately detect EGFR mutations is urgently needed. Methods: We evaluated the Idylla™ EGFR Mutation Assay for EGFR mutations in formalin-fixed, paraffin-embedded (FFPE) tumor samples from 232 lung cancer patients, and compared the results with amplification refractory mutation system (ARMS) (n=146) and next-generation sequencing (NGS) (n=86). The surgical tumor sections and cell blocks derived from the same FFPE section were compared. Overall concordance, specificity, sensitivity, cost-effectiveness and turnaround time were compared among the three methods. Results: The overall concordance between Idylla and ARMS was 89.51% [95% confidence interval (CI): 83.31% to 93.64%] and the specificity of Idylla was 88.68% (95% CI: 80.69% to 93.76%). A concordance of 97.67% (95% CI: 91.41% to 99.86%) was obtained between Idylla and NGS, the specificity of Idylla was 96.30% (95% CI: 86.16% to 99.36%). Compared to the ARMS and NGS, the Idylla™ system significantly reduces the turnaround time. Combining labor, equipment, reagents and time costs, Idylla is more affordable. Conclusions: Clinically urgent cases with adequate cellularity, can first perform Idylla to detect critical markers, then perform NGS for a comprehensive mutation analysis. Besides, with limited molecular expertise or infrastructure, the Idylla has the potential to extend EGFR testing to more pathology laboratories in primary hospitals.

Primary leptomeningeal melanocytic neoplasms: A clinicopathologic, immunohistochemical, and molecular study of 12 cases.

This study investigated the clinicopathological, immunohistochemical, and molecular features of primary leptomeningeal melanocytic neoplasms (LMNs). Twelve LMN cases were retrospectively reviewed. We performed Fluorescence in-situ hybridization (including a 4-probe FISH assay with CDKN2A and MYC assay) and Next-Generation sequencing analyses on available cases. Histologically, 2 tumours were classified as melanocytomas (MC), 2 as intermediate-grade melanocytomas (IMC), and 8 as leptomeningeal melanomas (LMM). Two rare cases of LMM were associated with large plaque-like blue nevus. One MC case was associated with Ota. Ten cases (83.3%) showed melanocytic cells with benign features diffusely proliferating within the meninges. The Ki-67 in three categories differed (MC 0-1%, IMC 0-3%, LMM 3-10%). 57.1% of LMM cases (4/7) were positive for FISH. Nine of 10 tumours harboured activating hotspot mutations in GNAQ, GNA11, or PLCB4. Additional mutations of EIF1AX, SF3B1, or BAP1 were found in 40%, 30%, and 10% of tumours, respectively. During the follow-up (median = 43 months), 5 LMM patients experienced recurrence and/or metastasis, 3 of them died of the disease and the other 2 are alive with the tumour. Our study is by far the first cohort of LMN cases tested by FISH. In addition to morphological indicators including necrosis and mitotic figures, using a combination of Ki-67 and FISH helps to differentiate between IMC and LMM, especially in LMM cases with less pleomorphic features. SF3B1 mutation is first described in 2 cases of plaque-type blue nevus associated with LMM. Patients with SF3B1 mutation might be related to poor prognosis in LMN.

YTHDF1 promotes the osteolytic bone metastasis of breast cancer via inducing EZH2 and CDH11 translation.

Bone metastasis is common in breast cancer and more effective therapies are required, however, its molecular mechanism is poorly understood. Additionally, the role of the m6A reader YTHDF1 in bone metastasis of breast cancer has not been reported. Here, we reveal that the increased expression of YTHDF1 is clinically correlated with breast cancer bone metastases. YTHDF1 promotes migration, invasion, and osteoblast adhesion and induces osteoclast differentiation of cancer cells in vitro and vivo. Mechanically, RNA-seq, MeRIP-seq and RIP-seq analysis, and molecular biology experiments demonstrate that YTHDF1 translationally enhances EZH2 and CDH11 expression by reading m6A-enriched sites of their transcripts. Moreover, adeno-associated virus (AAV) was used to deliver shYTHDF1 (shYTHDF1-AAV) in intratibial injection models, eliciting a significant suppressive effect on breast cancer bone metastatic formation and osteolytic destruction. Overall, we uncovered that YTHDF1 promotes osteolytic bone metastases of breast cancer by inducing EZH2 and CDH11 translation.

A custom next-generation sequencing panel for 1p/19q codeletion and mutational analysis in gliomas.

The World Health Organization has updated their classification system for the diagnosis of gliomas, combining histological features with molecular data including isocitrate dehydrogenase 1 and codeletion of chromosomal arms 1p and 19q. 1p/19q codeletion analysis is commonly performed by fluorescence in situ hybridization (FISH). In this study, we developed a 57-gene targeted next-generation sequencing (NGS) panel including 1p/19q codeletion detection mainly to assess diagnosis and potential treatment response in melanoma, gastrointestinal stromal tumor, and glioma patients. Loss of heterozygosity analysis was performed using the NGS method on 37 formalin-fixed paraffin-embedded glioma tissues that showed 1p and/or 19q loss determined by FISH. Conventional methods were applied for the validation of some glioma-related gene mutations. In 81.1% (30 of 37) and 94.6% (35 of 37) of cases, 1p and 19q were found to be in agreement whereas concordance for 1p/19q codeletion and no 1p/19q codeletion was found in 94.7% (18 of 19) and 94.4% (17 of 18) of cases, respectively. Overall, comparing NGS results with those of conventional methods showed high concordance. In conclusion, the NGS panel allows reliable analysis of 1p/19q codeletion and mutation at the same time.

Comprehensive analysis of next generation sequencing and ARMS-PCR for detecting EGFR exon 20 insertion (ex20ins) mutations in Chinese non-small cell lung cancer patients.

Background: Amivantamab (JNJ-372) and mobocertinib (TAK-788) have been reported to have favorable therapeutic effect for non-small cell lung cancer (NSCLC) patients with epidermal growth factor receptor (EGFR) exon 20 insertion (ex20ins) mutations. Thus, accurate detection of EGFR ex20ins mutations is crucial for subsequent individualized therapy. The aim of this study was to compare the two common methods of next generation sequencing (NGS) and amplification refractory mutation system polymerase chain reaction (ARMS-PCR) for detecting EGFR ex20ins mutations in Chinese NSCLC patients. Methods: We retrospectively analyzed EGFR mutations, especially for ex20ins, in 3,606 NSCLC patients detected by NGS and 1,785 patients by ARMS. Results: Among the 3,606 NGS patients, a total of 2,077 EGFR mutations and 95 EGFR ex20ins were identified, accounting for 57.6% and 2.6%, respectively. While 48.4% of EGFR mutations and 1.1% of ex20ins were detected in 1,785 ARMS patients, which were significantly lower than those of NGS (P<0.01). Thirty-four unique ex20ins variants were identified by NGS, and eight of them was reported for the first time. However, ARMS was designed to detect only several known EGFR ex20ins variants, and even did not include the most common variants in Chinese NSCLC patients. Conclusions: NGS is more advantageous and strongly recommended for the detection of EGFR ex20ins mutations. Considering the fast and cost-effective ARMS detection method, it is suggested that the primers design should be updated according to the characteristics of EGFR ex20ins mutations in Chinese NSCLC patients.

Characteristics and Clinical Value of MYC, BCL2, and BCL6 Rearrangement Detected by Next-generation Sequencing in DLBCL.

MYC, BCL2, and BCL6 rearrangements are clinically important events of diffuse large B-cell lymphoma (DLBCL). The ability and clinical value of targeted next-generation sequencing (NGS) in the detection of these rearrangements in DLBCL have not been fully determined. We performed targeted NGS (481-gene-panel) and break-apart FISH of MYC, BCL2, and BCL6 gene regions in 233 DLBCL cases. We identified 88 rearrangements (16 MYC; 20 BCL2; 52 BCL6 ) using NGS and 96 rearrangements (28 MYC; 20 BCL2; 65 BCL6) using FISH. The consistency rates between FISH and targeted NGS for the detection of MYC, BCL2, and BCL6 rearrangements were 93%, 97%, and 89%, respectively. FISH-cryptic rearrangements (NGS+/FISH-) were detected in 7 cases (1 MYC; 3 BCL2; 2 BCL6; 1 MYC::BCL6), mainly caused by small chromosomal insertions and inversions. NGS-/FISH+ were detected in 38 cases (14 MYC; 4 BCL2; 20 BCL6).To clarify the cause of the inconsistencies, we selected 17 from the NGS-/FISH+ rearrangements for further whole genome sequencing (WGS), and all 17 rearrangements were detected with break points by WGS. These break points were all located outside the region covered by the probe of targeted NGS, and most (16/17) were located in the intergenic region. These results indicated that targeted NGS is a powerful clinical diagnostics tool for comprehensive MYC, BCL2, and BCL6 rearrangement detection. Compared to FISH, it has advantages in describing the break point distribution, identifying uncharacterized partners, and detecting FISH-cryptic rearrangements. However, the lack of high-sensitivity caused by insufficient probe coverage is the main limitation of the current technology.

NOTCH1 Mutations Predict Superior Outcomes of Immune Checkpoint Blockade in Non-Small Cell Lung Cancer.

Background: NOTCH1 is frequently mutated in non-small cell lung cancer (NSCLC), and also is a poor therapeutic target. It is of clinical importance to investigate the effects of NOTCH1 mutations on anti-tumor immunity and response to immune checkpoint blockade (ICB). Methods: An observational study with targeted sequencing in 963 NSCLC patients at our center were performed (FUSCC cohort). Data of the Cancer Genome Atlas Pan-Lung Cancer study (TCGA cohort) were analyzed, and gene set enrichment analysis (GSEA) was performed. The Samstein et al cohort included 350 patients with advanced NSCLC undergoing genomic profiling with the MSK-IMPACT assay, and receiving at least one dose of ICB therapy. Results: NOTCH1 mutations were more common in smokers and patients with squamous-cell carcinoma (SCC) (all P value <0.05). For patients who did not receive ICB therapy (TCGA cohort), the overall survival (OS) of NOTCH1-mutant and -WT patients were comparable (log-rank P = 0.72), while for patients who received ICB therapy in the Samstein et al cohort, NOTCH1-mutant patients had significantly superior OS than WT patients (log-rank P = 0.041). On multivariate Cox analysis, the predictive value of NOTCH1 mutations reached marginal statistical significance (HR, 0.42; 95% CI, 0.17-1.04; P = 0.059). The median of TMB for NOTCH1-mutant tumors was significantly higher than that for NOTCH1-WT tumors, and GSEA revealed that NOTCH1 mutations manifested various defects in the repair of DNA damage. NOTCH1-mutant tumors displayed an inflamed tumor microenvironment (TME), manifesting as increased PD-L1 expression and tumor-infiltrating CD8+ T cells. Conclusion: NOTCH1 mutations define a molecular subtype of NSCLC, which are more common in smokers and patients with SCC, are characterized with higher TMB, inflamed TME, and display improved survival of ICB therapy for NSCLC patients.

The PIK3CA-E545K-SIRT4 signaling axis reduces radiosensitivity by promoting glutamine metabolism in cervical cancer.

The mutation of glutamic acid 545 to lysine (E545K) in PIK3CA, as the most common missense mutation of this gene in various cancer types, is frequently observed in cervical cancer and has been shown to reduce cervical cancer radiosensitivity. However, the underlying mechanisms remain unclear. Here, we implicate the alterations of glutamine metabolism in PIK3CA-E545K-mediated radioresistance of cervical cancer. Specifically, PIK3CA mutation negatively regulated the expression of SIRT4 via the epigenetic regulator EP300 independently of the canonical mTORC1 pathway. PIK3CA-E545K-induced SIRT4 downregulation promoted cell proliferation, migration, and radiation-induced DNA repair and apoptosis, while SIRT4 overexpression reversed the radioresistance phenotype mediated by PIK3CA mutation. Mechanistically, SIRT4 modulated glutamine metabolism and thus cellular apoptosis by negatively regulating a glutamate pyruvate transaminase GPT1. Moreover, the PI3K inhibitor BYL719, but not mTOR inhibitors, exerted remarkable synergistic effects with radiotherapy by inhibiting glutamine metabolism in vitro and in vivo. Collectively, this study reveals the role of PIK3CA-E545K-SIRT4 axis in regulating glutamine metabolism and the radioresistance in cervical cancer, which provides a necessary preliminary basis for clinical research of PI3K inhibitors as radiosensitizing agents.