Synthetical lethality of Werner helicase and mismatch repair deficiency is mediated by p53 and PUMA in colon cancer.

Synthetic lethality is a powerful approach for targeting oncogenic drivers in cancer. Recent studies revealed that cancer cells with microsatellite instability (MSI) require Werner (WRN) helicase for survival; however, the underlying mechanism remains unclear. In this study, we found that WRN depletion strongly induced p53 and its downstream apoptotic target PUMA in MSI colorectal cancer (CRC) cells. p53 or PUMA deletion abolished apoptosis induced by WRN depletion in MSI CRC cells. Importantly, correction of MSI abrogated the activation of p53/PUMA and cell killing, while induction of MSI led to sensitivity in isogenic CRC cells. Rare p53-mutant MSI CRC cells are resistant to WRN depletion due to lack of PUMA induction, which could be restored by wildtype (WT) p53 knock in or reconstitution. WRN depletion or treatment with the RecQ helicase inhibitor ML216 suppressed in vitro and in vivo growth of MSI CRCs in a p53/PUMA-dependent manner. ML216 treatment was efficacious in MSI CRC patient-derived xenografts. Interestingly, p53 gene remains WT in the majority of MSI CRCs. These results indicate a critical role of p53/PUMA-mediated apoptosis in the vulnerability of MSI CRCs to WRN loss, and support WRN as a promising therapeutic target in p53-WT MSI CRCs.

Blood flow regulates acvrl1 transcription via ligand-dependent Alk1 activity.

Hereditary hemorrhagic telangiectasia (HHT) is an autosomal dominant disease characterized by the development of arteriovenous malformations (AVMs) that can result in significant morbidity and mortality. HHT is caused primarily by mutations in bone morphogenetic protein receptors ACVRL1/ALK1, a signaling receptor, or endoglin (ENG), an accessory receptor. Because overexpression of Acvrl1 prevents AVM development in both Acvrl1 and Eng null mice, enhancing ACVRL1 expression may be a promising approach to development of targeted therapies for HHT. Therefore, we sought to understand the molecular mechanism of ACVRL1 regulation. We previously demonstrated in zebrafish embryos that acvrl1 is predominantly expressed in arterial endothelial cells and that expression requires blood flow. Here, we document that flow dependence exhibits regional heterogeneity and that acvrl1 expression is rapidly restored after reinitiation of flow. Furthermore, we find that acvrl1 expression is significantly decreased in mutants that lack the circulating Alk1 ligand, Bmp10, and that, in the absence of flow, intravascular injection of BMP10 or the related ligand, BMP9, restores acvrl1 expression in an Alk1-dependent manner. Using a transgenic acvrl1:egfp reporter line, we find that flow and Bmp10 regulate acvrl1 at the level of transcription. Finally, we observe similar ALK1 ligand-dependent increases in ACVRL1 in human endothelial cells subjected to shear stress. These data suggest that ligand-dependent Alk1 activity acts downstream of blood flow to maintain or enhance acvrl1 expression via a positive feedback mechanism, and that ALK1 activating therapeutics may have dual functionality by increasing both ALK1 signaling flux and ACVRL1 expression.

Clinical implications of additional chromosomal abnormalities in adult acute myeloid leukemia with inv (16)/t(16;16)/CBFB::MYH11.

OBJECTIVES: This study assesses the clinical significance of additional cytogenetic abnormalities (ACAs) and/or the deletion of 3'CBFB (3'CBFBdel) resulting in unbalanced CBFB::MYH11 fusion in acute myeloid leukemia (AML) with inv (16)/t(16;16)/CBFB::MYH11. METHODS: We retrospectively evaluated the clinicopathologic features of 47 adult de novo AML with inv (16)/t(16;16)/CBFB::MYH11 fusion. There were 44 balanced and 3 unbalanced CBFB::MYH11 fusions. Given the low frequency of unbalanced cases, the latter group was combined with 19 published cases (N = 22) for statistic and meta-analysis. RESULTS: Both balanced and unbalanced cases were characterized by frequent ACAs (56.5% and 72.7%, respectively), with +8, +22, and del(7q) as the most frequent abnormalities. The unbalanced group tends to be younger individuals (p = .04) and is associated with a lower remission rate (p = .02), although the median overall survival (OS) was not statistically different (p = .2868). In the balanced group, "ACA" subgroup had higher mortality (p = .013) and shorter OS (p = .011), and patients with relapsed disease had a significantly shorter OS (p = .0011). Cox multivariate regression analysis confirmed that ACAs and history of disease relapse are independent risk factors, irrespective of disease relapse status. In the combined cohort, cases with ACAs had shorter OS than those with "Sole" abnormality (p = .0109). CONCLUSIONS: ACAs are independent high-risk factors in adult AML with inv (16)/t(16;16)/CBFB::MYH11 fusion and should be integrated for risk stratification in this disease. Larger studies are needed to assess the clinical significance of the unbalanced CBFB::MYH11 fusion resulting from the 3'CBFBdel.

ROS1 Alterations as a Potential Driver of Gliomas in Infant, Pediatric, and Adult Patients.

Gliomas harboring oncogenic ROS1 alterations are uncommon and primarily described in infants. Our goal was to characterize the clinicopathological features and molecular signatures of the full spectrum of ROS1 fusion-positive gliomas across all age groups. Through a retrospective multi-institutional collaboration, we report a collection of unpublished ROS1 fusion gliomas along with the characterization and meta-analysis of new and published cases. A cohort of 32 new and 58 published cases was divided into the following 3 age groups: 19 infants, 40 pediatric patients, and 31 adults with gliomas. Tumors in infants and adults showed uniformly high-grade morphology; however, tumors in pediatric patients exhibited diverse histologic features. The GOPC::ROS1 fusion was prevalent (61/79, 77%) across all age groups, and 10 other partner genes were identified. Adult tumors showed recurrent genomic alterations characteristic of IDH wild-type glioblastoma, including the +7/-10/CDKN2A deletion; amplification of CDK4, MDM2, and PDGFRA genes; and mutations involving TERTp, TP53, PIK3R1, PIK3CA, PTEN, and NF1 genes. Infant tumors showed few genomic alterations, whereas pediatric tumors showed moderate genomic complexity. The outcomes were significantly poorer in adult patients. Although not statistically significant, tumors in infant and pediatric patients with high-grade histology and in hemispheric locations appeared more aggressive than tumors with lower grade histology or those in nonhemispheric locations. In conclusion, this study is the largest to date to characterize the clinicopathological and molecular signatures of ROS1 fusion-positive gliomas from infant, pediatric, and adult patients. We conclude that ROS1 likely acts as a driver in infant and pediatric gliomas and as a driver or codriver in adult gliomas. Integrated comprehensive clinical testing might be helpful in identifying such patients for possible targeted therapy.

m6A modulates haematopoietic stem and progenitor cell specification.

N6-methyladenosine (m6A) has been identified as the most abundant modification on eukaryote messenger RNA (mRNA). Although the rapid development of high-throughput sequencing technologies has enabled insight into the biological functions of m6A modification, the function of m6A during vertebrate embryogenesis remains poorly understood. Here we show that m6A determines cell fate during the endothelial-to-haematopoietic transition (EHT) to specify the earliest haematopoietic stem/progenitor cells (HSPCs) during zebrafish embryogenesis. m6A-specific methylated RNA immunoprecipitation combined with high-throughput sequencing (MeRIP-seq) and m6A individual-nucleotide-resolution cross-linking and immunoprecipitation with sequencing (miCLIP-seq) analyses reveal conserved features on zebrafish m6A methylome and preferential distribution of m6A peaks near the stop codon with a consensus RRACH motif. In mettl3-deficient embryos, levels of m6A are significantly decreased and emergence of HSPCs is blocked. Mechanistically, we identify that the delayed YTHDF2-mediated mRNA decay of the arterial endothelial genes notch1a and rhoca contributes to this deleterious effect. The continuous activation of Notch signalling in arterial endothelial cells of mettl3-deficient embryos blocks EHT, thereby repressing the generation of the earliest HSPCs. Furthermore, knockdown of Mettl3 in mice confers a similar phenotype. Collectively, our findings demonstrate the critical function of m6A modification in the fate determination of HSPCs during vertebrate embryogenesis.

Evaluating the prognosis of oral squamous cell carcinoma patients via L3 skeletal muscle index.

OBJECTIVES: This study aimed to construct a formula to predict L3 skeletal muscle cross-sectional area (CSA) from C3 CSA and to select the cutoff values to evaluate the nutritional status in OSCC. MATERIALS AND METHODS: A total of 220 OSCC patients in Nanfang Hospital were divided into two groups: the training set (n = 100) and the validation set (n = 120). Patients in the training set were performed the preoperative whole-body positron emission tomography-computed tomography (PET/CT) scans, and patients in the validation set received preoperative head-and-neck computed tomography (CT) scans. C3 CSA and L3 CSA were delineated. The predictive formula was established, and the gender-specific thresholds of malnutrition were obtained by X-tile software in training set. Finally, the formula and cutoff values were validated. RESULTS: The predictive formula was successfully established. The gender-specific cutoff values for L3 SMI were 55.0 cm2 /m2 for men and 36.6 cm2 /m2 for women. There were no differences between the overall survival (OS) of patients diagnosed with malnutrition and that of patients who are not malnutrition. CONCLUSIONS: Our studies reveal that the L3 CSA could be calculated by C3 CSA conveniently with our formula in OSCC, which allowed us to assess malnutrition with head-and-neck CT image. However, there is no direct connection found between malnutrition and OS in OSCC. Hence, further studies with a larger sample size may be required.

The complete mitochondrial genome of Morishitium polonicum (Trematoda, Cyclocoelidae) and its phylogenetic implications.

Trematodes can adversely impact the health and survival of wild animals. The trematode family Cyclocoelidae, which includes large digenean bird parasites, lacks molecular analysis, and reclassifications have not been supported. This study produced the first fully assembled and annotated mitochondrial genome sequence for the trematode Morishitium polonicum. The whole length of the M. polonicum (GenBank accession number: OP930879) mitogenome is 14083 bp, containing 22 transfer ribonucleic acids (tRNAs), 2 ribosomal RNAs (rRNAs, rrnL and rrnS), and a noncoding control section (D-loop) 13777 to 13854 bp in length. The 12 PCG areas have 3269 codons and a total length of 10053 bp, which makes up 71.38% of the mitochondrial genome's overall sequence. Most (10/12) of the PCGs that code for proteins begin with ATG, while the nad4L and nad1 genes have a GTG start codon. Phylogenetic analysis using the concatenated nucleotide sequences of 12 PCGs, and the ML tree analysis results showed that M. polonicum is more closely related to with Echinostomatidae and Fasciolidae, which indicates that the family Cyclocoelidae is more closely associated with Echinochasmidae. This study provides mtDNA information, and analysis of mitogenomic structure and evolution. Moreover, we aimed to understand the phylogenetic relationships of this fluke.

Comparison of myeloid neoplasms with nonclassic 3q26.2/MECOM versus classic inv(3)/t(3;3) rearrangements reveals diverse clinicopathologic features, genetic profiles, and molecular mechanisms of MECOM activation.

MECOM rearrangements are recurrent in myeloid neoplasms and associated with poor prognosis. However, only inv(3)(q21q26.2) and t(3;3)(q21;q26.2), the classic MECOM rearrangements resulting in RPN1-MECOM rearrangement with Mecom overexpression and GATA2 haploinsufficiency, define the distinct subtype of acute myeloid leukemia (AML), and serve as presumptive evidence for myelodysplastic syndrome based on the current World Health Organization classification. Myeloid neoplasms with nonclassic 3q26.2/MECOM rearrangements have been found to be clinically aggressive, but comparative analysis of clinicopathologic and genomic features is limited. We retrospectively studied cohorts of myeloid neoplasms with classic and nonclassic MECOM rearrangements. Cases with classic rearrangements consisted predominantly of AML, often with inv(3) or t(3;3) as the sole chromosome abnormality, whereas the group of nonclassic rearrangements included a variety of myeloid neoplasms, often with complex karyotype without TP53 mutations and similarly dismal overall survival. Immunohistochemistry revealed Mecom protein overexpression in both groups, but overexpression in cases with nonclassic rearrangements was mediated through a mechanism other than GATA2 distal enhancer involvement typical for classic rearrangement. Our results demonstrated that myeloid neoplasms with nonclassic 3q26.2/MECOM rearrangements encompass a diverse group of diseases with poor clinical outcome, overexpression of Mecom protein as a result of the nonclassic mechanism of MECOM activation.

Therapy-related myeloid neoplasms with normal karyotype show distinct genomic and clinical characteristics compared to their counterparts with abnormal karyotype.

Therapy-related myeloid neoplasms (t-MNs) are a complication of treatment with cytotoxic chemotherapy and/or radiation therapy. The majority of t-MNs show chromosomal abnormalities associated with myelodysplastic syndrome (MDS) or KMT2A rearrangements and are characterized by poor clinical outcomes. A small but substantial subset of patients have normal karyotype (NK) and their clinical characteristics and mutational profiles are not well studied. We retrospectively studied patients diagnosed with t-MN at three institutions and compared the mutational profile and survival data between t-MNs with NK and t-MNs with abnormal karyotype (AK). A total of 204 patients with t-MN were identified including 158 with AK and 46 with NK. NK t-MNs, compared to AK, were enriched for mutations in TET2 (p < 0.0001), NPM1 (p < 0.0001), ASXL1 (p = 0.0003), SRSF2 (p < 0.0001), RUNX1 (p = 0.0336) and STAG2 (p = 0.0099) and showed a significantly lower frequency of TP53 mutations (p < 0.0001). Overall survival (OS) was significantly lower in AK t-MNs as compared to NK cases (p = 0.0094). In our study, NK t-MNs showed a significantly better OS, a higher prevalence of MN-associated mutations and a lower frequency of TP53 mutations compared to their AK counterparts. The distinct clinical and mutational profile of NK t-MNs merits a separate classification.

Histological and molecular analysis of cellular leiomyoma with sclerosis: linked to HMGA2 overexpression.

HMGA2 overexpression is found in 10-15% of leiomyomas (LM). HMGA2 overexpression is common in variants of hydropic, intravenous and lipo-LM. Cellular or highly cellular LM (CLM) is a LM variant with a less well-defined molecular nature. In this study, we identified and examined 52 hypercellular LM with sclerotic collagen, herein defined as cellular leiomyoma with sclerosis (CLM-S). CLM-S shows large tumour size (average 12.2 cm) and characteristic histology of tumour cells, arranged in cellular fascicles, sheets and trabeculae with abundant dense, pink sclerotic extracellular matrix in bands and nodules and increased vascularity. Tumour cells are uniform with small, round-oval nuclei and scant, pale-eosinophilic to vacuolated cytoplasm reminiscent of pericytes. The differential diagnosis of CLM-S includes conventional CLM, endometrial stromal tumours and perivascular epithelioid cell tumour. Immunohistochemical profile [HMGA2, fumarate hydratase, smooth muscle markers, Melan A and HMB-45] and molecular alterations [by HMGA2 mRNA reverse transcription-polymerase chain reaction (RT-PCR), HMGA2 fluorescence in-situ hybridisation and MED12 sequencing] were analysed in comparison to matched myometrium and CLM controls. Remarkably, 96% (50 of 52) of CLM-S demonstrated diffuse positive immunoreactivity for HMGA2 and up to an 80-fold increase in HMGA2 mRNA, determined by RT-PCR. FISH analysis with break-part probes at intron 3 and the 5' UTR detected HMGA2 rearrangements in 47% (18 of 38) of CLM-S. All CLM-S retained expression of fumarate hydratase. No MED12 mutations were found in any CLM-S. Our findings show that CLM-S has unique and characteristic histomorphology probably driven by HMGA2 overexpression.

Uterine Leiomyosarcoma Associated With Leiomyoma With Bizarre Nuclei: Histology and Genomic Analysis of 2 Cases.

Leiomyoma with bizarre nuclei (LM-BN) is a rare variant of leiomyoma with overall benign clinical course. It has histologic features showing focal or diffuse nuclear atypia surrounded by usual type leiomyoma. Uterine leiomyosarcomas (LMS) are a group of rare and aggressive malignancies with limited treatment options available. The potential association between LM-BN with LMS is largely unknown. In this study, we report 2 cases of uterine smooth muscle tumor with typical histologic and molecular evidence of LM-BN, which are associated with its progression to the malignant counterpart of LMS. We summarize the detailed histologic, morphologic, and genomic characteristics of these 2 sets of cases. Our findings suggest that LMS progressing from preexisting LM-BN can be one of the tumor pathogenesis pathways in uterine leiomyosarcomas.

Adjunctive Er:YAG laser in non-surgical periodontal therapy of patients with inadequately controlled type 2 diabetes mellitus: A split-mouth randomized controlled study.

BACKGROUND AND OBJECTIVE: Limited studies are available comparing the outcomes of non-surgical periodontal therapy (NSPT) with or without adjunctive Er:YAG laser (ERL) in patients with type 2 diabetes mellitus (T2DM). This study evaluated the effects of ERL adjunctive NSPT on single-rooted teeth of inadequately controlled T2DM patients with periodontitis. METHODS: Twenty-two inadequately controlled T2DM participants with periodontitis were recruited. Adopting a double-blinded split-mouth design and under block randomization, we investigated the effects of ERL in calculus removal then degranulation mode, or a sham treatment, adjunct NSPT, which included two visits of full-mouth root surface debridement delivered within 4-10 days, to test or control single-rooted teeth (Wuxi Stomatology Hospital, trial 2017-016). We followed periodontal parameters (plaque %, bleeding on probing [BOP] %, probing pocket depth [PPD], probing attachment level [PAL]) and selected systemic parameters (fasting plasma glucose [FPG], glycosylated hemoglobin [HbA1c%], high sensitivity C-reactive protein) at baseline, one, three, and six months after periodontal treatment. RESULTS: The study was completed as planned. Periodontal parameters, FPG and HbA1c% of the 22 participants appeared significantly improved at six months (p < 0.001). The 44 ERL treated, compared to 44 sham treated single-rooted teeth exhibited significant improvement in BOP, mean PPD, and mean PAL at various postoperative follow-up time points (effect size ≥0.44; p < 0.001). No adverse event was reported. CONCLUSION: Periodontal treatment outcomes in the T2DM patients with inadequate glycemic control were better in the single-rooted teeth received ERL adjunct NSPT. Further studies are warranted to confirm the observations reported in this short-term clinical study.

Rac2 Regulates the Migration of T Lymphoid Progenitors to the Thymus during Zebrafish Embryogenesis.

The caudal hematopoietic tissue in zebrafish, the equivalent to the fetal liver in mammals, is an intermediate hematopoietic niche for the maintenance and differentiation of hematopoietic stem and progenitor cells before homing to the thymus and kidney marrow. As one of the ultimate hematopoietic organs, the thymus sustains T lymphopoiesis, which is essential for adaptive immune system. However, the mechanism of prethymic T lymphoid progenitors migrating to the thymus remains elusive. In this study, we identify an Rho GTPase Rac2 as a modulator of T lymphoid progenitor homing to the thymus in zebrafish. rac2-Deficient embryos show the inability of T lymphoid progenitors homing to the thymus because of defective cell-autonomous motility. Mechanistically, we demonstrate that Rac2 regulates homing of T lymphoid progenitor through Pak1-mediated AKT pathway. Taken together, our work reveals an important function of Rac2 in directing T lymphoid progenitor migration to the thymus during zebrafish embryogenesis.

Potential association of bone mineral density loss with cognitive impairment and central and peripheral amyloid-ß changes: a cross-sectional study.

BACKGROUND: There is some evidence in the literature that older adults with cognitive impairments have a higher risk for falls and osteoporotic hip fractures. Currently, the associations between bone health and cognitive health have not been extensively studied. Thus, the present cross-sectional study aims to investigate the relationship between markers of bone loss and cognitive performance in older adults with and without osteopenia as well as older adults with cognitive impairments (i.e., Alzheimer's disease [AD]). METHODS: Sixty-two non-osteopenia participants and one hundred three osteopenia participants as the cohort 1 and 33 cognitively normal non-AD participants and 39 AD participants as the cohort 2 were recruited. To assess cognitive and bone health, hip bone mineral density (BMD) and cognitive performance (via Minimal Mental State Examination [MMSE] and/or Auditory Verbal Learning Test-delayed recall [AVLT-DR]) were assessed. Furthermore, in cohort 1, plasma amyloid-ß (Aß) levels, and in cohort 2, cerebrospinal fluid (CSF) Aß levels were determined. RESULTS: We observed that (1) compared with non-osteopenia participants, BMD values (t = - 22.806; 95%CI: - 1.801, - 1.484; p < 0.001), MMSE scores (t = - 5.392; 95%CI: - 3.260, - 1.698; p < 0.001), and AVLT-DR scores (t = - 4.142; 95%CI: - 2.181, - 0.804; p < 0.001), plasma Aß42 levels (t = - 2.821; 95%CI: - 1.737, - 0.305; p = 0.01), and Aß42/40 ratio (t = - 2.020; 95%CI: - 0.009, - 0.001; p = 0.04) were significantly lower in osteopenia participants; (2) plasma Aß42/40 ratio showed a mediate effect for the association between BMD values and the performance of cognitive function in osteopenia participants by mediation analysis, adjusting age, sex, years of education, and body mass index (BMI); (3) BMD values (95%CI: - 1.085, 0.478; p < 0.001) were significantly reduced in AD participants as compared with cognitively normal non-AD participants; (4) in AD participants, the interactive effects of BMD and CSF Aß42/40 ratio on MMSE scores was found by regression analysis, controlling age, sex, years of education, and BMI; (5) BMD can distinguish AD participants from cognitively normal non-AD participants with AUC of 0.816 and distinguish participants with the cognitive impairment from cognitively normal participants with AUC of 0.794. CONCLUSION: Our findings suggest a relationship between bone health and cognitive health. Given the correlations between BMD and important markers of cognitive health (e.g., central and peripheral pathological change of Aß), BMD might serve as a promising and easy-accessible biomarker. However, more research is needed to further substantiate our findings.

Characterization of the complete mitochondrial genome of Ixodes granulatus (Ixodidae) and its phylogenetic implications.

Ticks are deemed to be second only to mosquitoes as the most common vector of human infectious diseases worldwide that give rise to human and animal diseases and economic losses to livestock production. Our understanding of the phylogenetic analysis between tick lineages has been restricted by the phylogenetic markers of individual genes. Genomic data research could help advance our understanding of phylogenetic analysis and molecular evolution. Mitochondrial genomic DNA facilitated the phylogenetic analysis of eukaryotes containing ticks. In this study, we sequenced and assembled the circular complete mitogenome information of Ixodes granulatus. The 14,540-bp mitogenome consists of 37 genes, including 13 protein-coding genes (PCGs), two genes for ribosomal RNA (rRNAs), and 22 genes for transfer RNA (tRNAs), and the origin of the L-strand replication region. The directions of the coding strand and component genes in the non-Australasian Ixodes mitochondrial genome were similar to those found in most other Australasian Ixodes, except for the loss of a lengthy control region. The phylogenetic tree based on maximum likelihood (ML) and Bayesian inference (BI) computational algorithms showed that I. granulatus exhibits a close relationship with I. hexagonus and I. ricinus. To our knowledge, this is the first study exploring the complete mitogenome for the species I. granulatus. Our results provide new insights for further research on the evolution, population genetics, systematics, and molecular ecology of ticks.

Characterization of the complete mitochondrial genome of Haemaphysalis (Alloceraea) kolonini (Ixodidae) and its phylogenetic implications.

Ticks transmit diverse pathogens that cause human and animal diseases, leading to an increasing number of new challenges around the world. Genomic data research could help advance our learning of phylogenetic analysis and molecular evolution. Mitochondrial genome DNA has been helpful in illustrating the phylogenetic analysis of eukaryotes containing ticks. In this research, we sequenced and assembled the circular complete mitogenome information of Haemaphysalis kolonini. The 14,948-bp mitogenome consists of 37 genes which included 13 genes for protein-coding, two genes for ribosomal RNA, 22 genes for transfer RNA, and two control regions (D-loops). Overall, the composition and arrangement of genes were compared with Haemaphysalis ticks previously recorded in Genbank. The phylogenetic tree based on Maximum likelihood (ML) and Bayesian inference (BI) computational algorithms showed that H. kolonini has a close relationship with Haemaphysalis inermis. The complete mitogenome data provide a preferable perception to the phylogenetic relationship than the single-gene data analysis. To our knowledge, this is the first research exploring the complete mitogenome for the species H. kolonini. Our results provide new insights for further research on the evolution, population genetics, systematics, and molecular ecology of ticks.

Integrated histologic and molecular analysis of uterine leiomyosarcoma and 2 benign variants with nuclear atypia.

Uterine leiomyosarcoma (LMS) is a rare but deadly disease. Due to poor understanding of the molecular and genetic causes of the disease, the diagnosis of LMS has been based primarily on histology. Nuclear atypia is one of hallmarks in LMS, however, it also occurs in 2 clinically benign variants, including smooth muscle tumors with fumarate hydratase alteration (SMT-FH) and leiomyoma with bizarre nuclei (LM-BN). In addition to nuclear atypia, many well recognized biomarkers used for LMS are also frequently overexpressed in LM-BN, and the histogenesis and molecular natures for LM-BN and LMS remain largely unknown. To characterize the molecular profiling of LMS, SMT-FH, and LM-BN, we performed integrated comprehensive genomic profiling including whole-genome sequencing (WGS) and RNA sequencing and genomic microarray analyses to assess genome-wide copy number alterations (CNAs) and immunohistochemistry (IHC) in all 3 tumor types. We found that both LM-BN and LMS showed genomic instability and harbored extensive CNAs throughout the whole genome. By contrast, the SMT-FH presented its characteristic 1q43-44 deletions in all cases tested, with minimal CNAs in the rest of genomic regions. Further analyses revealed that LMS and LM-BN groups showed similar patterns of CNAs that are tended to cluster together and separated from the SMT-FH group. The integrated molecular profiling enabled the detection of novel and traditional biomarkers and showed excellent discrimination between LM-BN and LMS. Our study suggests that LM-BN, despite having similar nuclear atypia to SMT-FH, showed similar genomic instability but distinct genomic alterations with its malignant counterpart of LMS. The integrated molecular profiling is of clinical importance in characterizing these rare uterine smooth muscle tumors.

RNA m6A methylation promotes the formation of vasculogenic mimicry in hepatocellular carcinoma via Hippo pathway.

Vasculogenic mimicry (VM) formed by aggressive tumor cells to mimic vasculogenic networks plays an important role in the tumor malignancy of HCC. However, the pathogenesis underlying VM is complex and has not been fully defined. m6A is a common mRNA modification and has many biological effects. However, the relationship between m6A and VM remains unclear. In this research, we found that m6A methyltransferase METTL3 in HCC tissues was positively correlated with VM. The m6A level of mRNA significantly increased in 3D cultured cells treated with VEGFa and was related to VM formation. Transcriptome sequencing analysis of 3D cultured cells with knockdown Mettl3 showed that the Hippo pathway was involved in m6A-mediated VM formation. Further mechanism research indicated that the m6A modification of YAP1 mRNA affected the translation of YAP1 mRNA. In conclusion, m6A methylation plays a key role in VM formation in HCC. METTL3 and YAP1 could be potential therapeutic targets via impairing VM formation in anti-metastatic strategies.

The survival impact of CKS1B gains or amplification is dependent on the background karyotype and TP53 deletion status in patients with myeloma.

Gains or amplification (amp) of chromosome 1q21/CKS1B are reported to be a high-risk factor in myeloma. In this retrospective study, we analyzed the impact of CKS1B gain/amp on overall survival in the context of other genetic aberrations, such as TP53 deletion, FGFR3-IGH, IGH-MAF, MYEOV/CCND1-IGH, and RB1, as well as karyotype. The cohort included 132 myeloma patients with CKS1B gain/amp detected by fluorescence in-situ hybridization. There were 72 men and 60 women with a median age of 65 years (range 39-88 years). A normal, simple, or complex karyotype was observed in 39.5%, 5.4%, and 55% of patients, respectively. "Double hit," defined as CKS1B gain/amp coexisting with TP53 deletion, or "triple hit," defined as double hit plus t(4;14)FGFR3-IGH or t(14;16)IGH-MAF, were identified in 25 patients (18.9%) and five patients (3.8%), respectively. Double and triple hit were highly associated with a complex karyotype (p = 0.02). Ninety-nine patients (99/128, 77.3%) received stem cell transplantation. The median follow-up time was 48.2 months (range 2-104 months); 68 patients (51.5%) died, with a median overall survival of 58.8 months. Multivariate analysis (Cox model) showed that double hit with TP53 deletion (p = 0.0031), triple hit (p = 0.01), and complex karyotype (p = 0.0009) were each independently associated with poorer overall survival. Stem cell transplantation was associated with better overall survival, mainly in patients with a double or triple hit and complex karyotype (p = 0.003). These findings indicate that the inferior outcome of myeloma patients with CKS1B gain/amp is attributable to the high number of high-risk patients in this group. The prognostic impact of CKS1B gain/amp depends on the background karyotype and TP53 status.

Distinctive Clinicopathologic Features of Monomorphic B-cell Post-transplant Lymphoproliferative Disorders in Children.

INTRODUCTION: Post-transplant lymphoproliferative disorders (PTLDs) comprise a heterogeneous group of Epstein-Barr virus (EBV)-positive or negative lymphoid or plasmacytic lesions in solid organ or hematopoietic stem cell (HSC) transplant recipients. Although PTLDs in adults have been extensively studied, the clinicopathologic features of monomorphic B-cell PTLD in children, particularly EBV-negative forms, are still poorly understood. METHODS: We retrospectively reviewed all our pediatric cases of monomorphic B-cell PTLDs diagnosed in the past 10 years. Clinical data were reviewed. Pathologic data including histologic types and EBV status were analyzed. Additional immunohistochemical stains, FISH studies, and TP53 gene mutational status were performed. RESULTS: 4 of 18 cases were EBV-negative. All 4 EBV-negative cases were strikingly confined to the gastrointestinal (GI) tract or abdominal lymph nodes, while tumors in EBV-positive cases were found at various anatomic sites; 2 of 4 EBV-negative cases carried mutations in TP53 gene. Our cohort also included 2 rare types of PTLD, one plasmablastic lymphoma and one high-grade B-cell lymphoma, not otherwise specified (HGBL, NOS). CONCLUSION: We report that monomorphic B-cell PTLDs in children have distinctive clinical and pathological features. More studies are needed to clarify whether and how much these pediatric PTLDs differ from their adult counterparts.