EML4-ALK fusions drive lung adeno-to-squamous transition through JAK-STAT activation.

Human lung adenosquamous cell carcinoma (LUAS), containing both adenomatous and squamous pathologies, exhibits strong cancer plasticity. We find that ALK rearrangement is detectable in 5.1-7.5% of human LUAS, and transgenic expression of EML4-ALK drives lung adenocarcinoma (LUAD) formation initially and squamous transition at late stage. We identify club cells as the main cell-of-origin for squamous transition. Through recapitulating lineage transition in organoid system, we identify JAK-STAT signaling, activated by EML4-ALK phase separation, significantly promotes squamous transition. Integrative study with scRNA-seq and immunostaining identify a plastic cell subpopulation in ALK-rearranged human LUAD showing squamous biomarker expression. Moreover, those relapsed ALK-rearranged LUAD show notable upregulation of squamous biomarkers. Consistently, mouse squamous tumors or LUAD with squamous signature display certain resistance to ALK inhibitor, which can be overcome by combined JAK1/2 inhibitor treatment. This study uncovers strong plasticity of ALK-rearranged tumors in orchestrating phenotypic transition and drug resistance and proposes a potentially effective therapeutic strategy.

Modified Hepatic Arterial Infusion Chemotherapy Combined with Lenvatinib and Camrelizumab for Advanced HCC: Two Case Reports.

Background: Advanced-stage hepatocellular carcinoma (HCC), especially huge HCC or portal vein tumour thrombus (PVTT), is difficult to treat, and the prognosis is poor. The advantages of hepatic artery infusion chemotherapy (HAIC) combined with targeted therapy and immunotherapy for this complex disease are gradually becoming apparent. However, HAIC still has some inevitable disadvantages, such as arterial perfusion therapy requiring a long time, which results in many patients having difficulty completing the procedure. Modified HAIC (mHAIC)-based oxaliplatin and S-1 is a new treatment option for huge HCC or PVTT that can reduce complications and improve patient compliance. We report two cases of huge HCC or PVTT that were successfully treated with mHAIC combined with lenvatinib and camrelizumab. The clinical presentations, treatment strategies, and outcomes of these cases are presented. Case Presentation: Case 1: A 52-year-old female was found to have a huge HCC with a size of 14×11 cm. She was treated with one cycle of mHAIC combined with transcatheter arterial chemoembolization (TACE), lenvatinib and camrelizumab and 3 cycles of mHAIC in combination with lenvatinib and camrelizumab. The patient's follow-up maintenance therapy with lenvatinib and camrelizumab has been evaluated for efficacy in achieving complete response (CR). Case 2: A 57-year-old man was diagnosed with advanced HCC in combination with PVTT. He achieved partial remission (PR) after four cycles of mHAIC combined with lenvatinib and camrelizumab. This was followed by treatment with lenvatinib and camrelizumab with an efficacy assessment for CR, and progression-free survival (PFS) was 7 months. Conclusion: For advanced HCC with a large mass or PVTT, mHAIC combined with lenvatinib and camrelizumab is a safe and effective treatment with good patient compliance.

Novel exosome-related risk signature as prognostic biomarkers in glioblastoma.

Exosomes are progressively being detected as an indicator for the diagnosis and prognosis of cancer in clinical settings. Many clinical trials have confirmed the impact of exosomes on tumor growth, particularly in anti-tumor immunity and immunosuppression of exosomes. Therefore, we developed a risk score based on genes found in glioblastoma-derived exosomes. In this study, we used the TCGA dataset as the training queue and GSE13041, GSE43378, GSE4412, and CGGA datasets as the external validation queue. Based on machine algorithms and bioinformatics methods, an exosome-generalized risk score was established. We found that the risk score could independently predict the prognosis of patients with glioma, and there were significant differences in the outcomes of patients in the high- and low-risk groups. Univariate and multivariate analyses showed that risk score is a valid predictive biomarker for gliomas. Two immunotherapy datasets, IMvigor210 and GSE78220, were obtained from previous studies. A high-risk score showed a significant association with multiple immunomodulators that could act on cancer immune evasion. The exosome-related risk score could predict the effectiveness of anti-PD-1 immunotherapy. Moreover, we compared the sensitivity of patients with high- and low-risk scores to various anti-cancer drugs and found that patients with high-risk scores had better responses to a variety of anti-cancer drugs. The risk-scoring model established in this study provides a useful tool to predict the total survival time of patients with glioma and guide immunotherapy.

Case report and literature review: PET/CT in the evaluation of response to treatment of liver metastasis from colorectal cancer with DEBIRI-TACE.

Background: Irinotecan-loaded drug-eluting beads transarterial chemoembolization (DEBIRI-TACE) is a safe and effective therapeutic option for unresectable colorectal liver metastases (CRLM). The evaluation of treatment response after DEBIRI-TACE is very important for assessing the patient's condition. At present, the Response Evaluation Criteria in Solid Tumors (RECIST) with the tumor size obtained by CT and/or MRI and PET Response Criteria in Solid Tumors (PERCIST) based on fluorodeoxyglucose-positron emission tomography/computed tomography (FDG PET/CT) are used for evaluating the response to therapy of solid tumors; however, their value in the assessment of treatment response after DEBIRI-TACE remains unclear. Case presentation: A 52-year-old male with unresectable simultaneous CRLM was treated in the Affiliated Hospital of Yanbian University with DEBIRI-TACE combined with systemic chemotherapy and targeted therapy. Carcinoembryonic antigen levels decreased by 82.50% after 27 days of treatment. At 6 weeks post-surgery, FDG-PET/CT showed that the maximum standardized uptake value (SUVmax) of intrahepatic lesions was reduced to 62.14%. Abdominal MRI revealed that the sum of target lesion diameters was less than 30% that at baseline. PERCIST indicated partial metabolic response, whereas RECIST suggested stable disease. Conclusion: FDG PET/CT-based PERCIST may be accurate in determining treatment response and evaluating patient prognosis after DEBIRI-TACE in unresectable CRLM.

Maternal mRNA deadenylation and allocation via Rbm14 condensates facilitate vertebrate blastula development.

Early embryonic development depends on proper utilization and clearance of maternal transcriptomes. How these processes are spatiotemporally regulated remains unclear. Here we show that nuclear RNA-binding protein Rbm14 and maternal mRNAs co-phase separate into cytoplasmic condensates to facilitate vertebrate blastula-to-gastrula development. In zebrafish, Rbm14 condensates were highly abundant in blastomeres and markedly reduced after prominent activation of zygotic transcription. They concentrated at spindle poles by associating with centrosomal γ-tubulin puncta and displayed mainly asymmetric divisions with a global symmetry across embryonic midline in 8- and 16-cell embryos. Their formation was dose-dependently stimulated by m6 A, but repressed by m5 C modification of the maternal mRNA. Furthermore, deadenylase Parn co-phase separated with these condensates, and this was required for deadenylation of the mRNAs in early blastomeres. Depletion of Rbm14 impaired embryonic cell differentiations and full activations of the zygotic genome in both zebrafish and mouse and resulted in developmental arrest at the blastula stage. Our results suggest that cytoplasmic Rbm14 condensate formation regulates early embryogenesis by facilitating deadenylation, protection, and mitotic allocation of m6 A-modified maternal mRNAs, and by releasing the poly(A)-less transcripts upon regulated disassembly to allow their re-polyadenylation and translation or clearance.

Comparative Study of Application of Computed Tomography/Ultrasound and Computed Tomography Imaging Guidance Methods in the Microwave Ablation of Liver Cancer.

PURPOSE: The aim of the study is to assess the clinical value of the combined computed tomography (CT)/ultrasound (US) guidance in microwave ablation (MWA) for hepatocellular carcinoma (HCC). METHODS: From July 16, 2016, to June 20, 2021, medical records of 150 HCC patients treated with MWA were retrospectively analyzed. Ninety-two patients with 115 liver tumors underwent MWA under combined CT/US guidance, and 58 patients with 73 liver tumors received MWA under CT guidance alone. The clinical efficacy of combined CT/US-guided MWA was analyzed. We compared the complications, procedure time, and CT scan times between the 2 groups. RESULTS: The total complete ablation rate and complete ablation rate of high-risk location tumors were significantly higher in the group treated with combined CT/US guidance ( P = 0.0471 and P = 0.0347, respectively), the imaging guidance modality (odds ratio, 0.303; 95% confidence interval [CI], 0.095-0.970; P = 0.044) was an independent factor for ablation efficacy. These 2 groups also had significant differences in the procedure time ( P = 0.0171), the incidence rate of pneumothorax ( P = 0.0209), abdominal pain ( P = 0.0196), nausea or vomiting ( P = 0.0026), and intraoperative CT scan times ( P < 0.001). The overall complication rates ( P = 0.4023) and recurrence rates ( P = 0.5063) between the 2 groups were not statistically significant. However, CT/US group has a better short-term progressive free survival (log-rank P = 0.103, Breslow P = 0.030). In multivariate analysis, guidance modality (hazard ratio, 0.586; 95% CI, 0.368-0.934; P = 0.025) and Barcelona Clinic Liver Cancer stage (hazard ratio, 2.933; 95% CI, 1.678-5.127; P < 0.001) were risk factor for progressive free survival. CONCLUSIONS: Percutaneous MWA under the combined CT/US guidance for HCC can improve clinical benefits.

PRDX1 Influences The Occurrence and Progression of Liver Cancer by Inhibiting Mitochondrial Apoptosis Pathway.

OBJECTIVE: The aim of this study is to elucidate the role of PRDX1 in hepatocellular carcinoma using hepatoma cells. MATERIALS AND METHODS: In this experimental study, we elucidated role of PRDX1, using hepatoma cell lines. RESULTS: PRDX1 was upregulated in different types of cancers, including lung adenocarcinoma, breast cancer and liver cancer reported by several studies. nevertheless, mechanism of inducing liver cell death by PRDX1 remains largely unknown. Here, we showed that PRDX1 expression is enhanced in different cell lines. Here, we used western blot, quantitative real time polymerase chain reaction (qRT-PCR) and different biochemical assays to explore the role of PRDX1. We observed that overexpression of PRDX1 significantly enhanced proliferation of hepatoma cell lines, while knock-down of this gene showed significant inhibitory effects. We found that knock-down of PRDX1 activated cleaved caspase-3, caspase-9 proteins and Poly [ADP-ribose] polymerase 1 (PARP-1), which further executed apoptotic process, leading to cell death. We found that PRDX1 knock-down significantly produced mitochondrial fragmentation. We showed that silencing PRDX1 led to the loss of B-cell lymphoma 2 (Bcl-2) and activated Bcl-2-like protein 11 (Bim) which further induced Bax activation. Bax further released cytochrome c from mitochondria and induced apoptotic proteins, suggesting a significant role of PRDX1 knock-down in apoptosis. Finally, we showed that knock-down of PRDX1 significantly activated expression of Dynein-related protein 1 (Drp1), fission 1 (Fis1) and dynamin-2 (Dyn2) suggesting a crucial role of PRDX1 in mitochondrial fragmentation and apoptosis conditions. This study highlighted an important role of PRDX1 in regulating proliferation of hepatoma cells and thus future studies are required to validate its effect on hepatcoytes. CONCLUSION: We propose that future works on PRDX1 inhibitors may act as a therapeutic candidate for treatment of liver cancer.

Corrigendum: Antimicrobial susceptibility profiles and tentative epidemiological cutoff values of Legionella pneumophila from environmental water and soil sources in China.

[This corrects the article DOI: 10.3389/fmicb.2022.924709.].

Antimicrobial susceptibility profiles and tentative epidemiological cutoff values of Legionella pneumophila from environmental water and soil sources in China.

Legionnaires' disease (LD), caused by Legionella, including the most prevalent Legionella pneumophila, has been treated primarily with antibiotics. Environmental water and soil are the reservoirs for L. pneumophila. Studying antimicrobial susceptibility using a large number of isolates from various environmental sources and regions could provide an unbiased result. In the present study, antimicrobial susceptibility of 1464 environmental L. pneumophila isolates that were derived from various environmental water and soil sources of 12 cities in China to rifampin (RIF), erythromycin (ERY), clarithromycin (CLA), azithromycin (AZI), ciprofloxacin (CIP), moxifloxacin (MOX), levofloxacin (LEV), and doxycycline (DOX) was investigated, and minimum inhibitory concentration (MIC) data were obtained. We show that regarding macrolides, ERY was least active (MIC90 = 0.5 mg/L), while CLA was most active (MIC90 = 0.063 mg/L). A total of three fluoroquinolones have similar MICs on L. pneumophila. Among these antimicrobials, RIF was the most active agent, while DOX was the most inactive one. We observed different susceptibility profiles between serogroup 1 (sg1) and sg2-15 or between water and soil isolates from different regions. The ECOFFs were ERY and AZI (0.5 mg/L), RIF (0.002 mg/L), CIP, CLA and MOX (0.125 mg/L), LEV (0.063 mg/), and DOX (32 mg/L). Overall, two fluoroquinolone-resistant environmental isolates (0.14%) were first documented based on the wild-type MIC distribution. Not all azithromycin-resistant isolates (44/46, 95.65%) harbored the lpeAB efflux pump. The MICs of the ERY and CLA on the lpeAB + isolates were not elevated. These results suggested that the lpeAB efflux pump might be only responsible for AZI resistance, and undiscovered AZI-specific resistant mechanisms exist in L. pneumophila. Based on the big MIC data obtained in the present study, the same defense strategies, particularly against both CLA and RIF, may exist in L. pneumophila. The results determined in our study will guide further research on antimicrobial resistance mechanisms of L. pneumophila and could be used as a reference for setting clinical breakpoints and discovering antimicrobial-resistant isolates in the clinic, contributing to the antibiotic choice in the treatment of LD.

Presence of Viable, Clinically Relevant Legionella Bacteria in Environmental Water and Soil Sources of China.

The distribution of pathogenic Legionella in the environmental soil and water of China has not been documented yet. In this study, Legionella was detected in 129 of 575 water (22.43%) and 41 of 442 soil samples (9.28%) by culture. Twelve Legionella species were identified, of which 11 were disease-associated. Of the Legionella-positive samples, 109 of 129 (84.50%) water and 29 of 41 (70.73%) soil were positive for L. pneumophila, which accounted for about 75% of Legionella isolates in both water and soil, suggesting L. pneumophila was the most frequent species. Soil showed a higher diversity of Legionella spp. as compared with water (0.6279 versus 0.4493). In contrast, serogroup (sg) 1 was more prevalent among L. pneumophila isolates from water than from soil (26.66% versus 12.21%). Moreover, many disease-associated sequence types (STs) of L. pneumophila were found in China. Intragenic recombination was acting on L. pneumophila from both water and soil. Phylogeny, population structure, and molecular evolution analyses revealed a probable existence of L. pneumophila isolates with a special genetic background that is more adaptable to soil or water sources and a small proportion of genetic difference between water and soil isolates. The detection of viable, clinically relevant Legionella demonstrates soil as another source for harboring and dissemination of pathogenic Legionella bacteria in China. Future research should assess the implication in public health with the presence of Legionella in the soil and illustrate the genetic and pathogenicity difference of Legionella between water and soil, particularly the most prevalent L. pneumophila. IMPORTANCE Pathogenic Legionella spp. is the causative agent of Legionnaires' disease (LD), and L. pneumophila is the most common one. Most studies have focused on L. pneumophila from water and clinical samples. However, the soil is another important reservoir for this bacterium, and the distribution of Legionella spp. in water and soil sources has not been compared and documented in China yet. Discovering the distribution of Legionella spp. and L. pneumophila in the two environments may help a deep understanding of the pathogenesis and molecular evolution of the bacterium. Our research systematically uncovered the distributions of Legionella spp. in different regions and sources (e.g., water and soil) of China. Moreover, phylogeny, population structure, and molecular evolution study revealed the possible existence of L. pneumophila with a special genetic background that is more adaptable to soil or water sources, and genetic difference may exist.

Toll-like receptor 10 expression in B cells is negatively correlated with the progression of primary Sjögren's disease.

Primary Sjögren's Disease (pSjD) is considered a B cell-mediated disease. Toll-like receptor 10 (TLR10) is highly expressed in human B cells, indicating that TLR10 probably plays a vital role in pSjD. We examined TLR10 expression in peripheral B subsets of pSjD patients and analyzed their association with disease activity. We observed that TLR10 expression in total, naïve, memory, and switched memory B cells was significantly increased in low-activity pSjD patients as compared with healthy controls and high-activity patients. TLR10 expression in the above mentioned B subsets (except naïve B) was negatively correlated with serum levels of anti-SSA antibody and BAFF, respectively. Moreover, a higher proportion of high-activity pSjD patients was observed in TLR10 low- than high-expressed patients. Our study concluded that TLR10 expression in CD19+ B and memory B was negatively correlated with pSjD disease activity, suggesting that TLR10 might take part in the progression of pSjD.

Immune Cell Infiltration and Relevant Gene Signatures in the Tumor Microenvironment that Significantly Associates With the Prognosis of Patients With Breast Cancer.

Breast cancer is the most common malignancy and the leading cause of cancer-related deaths in women. Recent studies have investigated the prognostic value of the tumor microenvironment (TME)-related genes in breast cancer. The purpose of this research is to identify the immune-associated prognostic signature for breast cancer evaluate the probability of their prognostic value and compare the current staging system. In this study, we comprehensively evaluated the infiltration patterns of TME in 1,077 breast cancer patients downloaded from TCGA by applying the ssGSEA method to the transcriptome of these patients. Thus, generated two groups of immune cell infiltration. Based on two groups of low infiltration and high infiltration immune cell groups, 983 common differentially expressed genes were found using the limma algorithm. In addition, studying potential mechanisms, the GSEA method was used to indicate some pathways with remarkable enrichment in two clusters of immune cell infiltration. Finally, the seven immune-associated hub genes with survival as prognostic signatures were identified by using univariate Cox, survival, and LASSO analyses and constructed a TME score. The prognostic value of the TME score was self-validated in the TCGA cohort and further validated in an external independent set from METABRIC and GEO database by time-dependent survival receiver operation. Univariate and multivariate analyses of clinicopathological characteristics indicated that the TME score was an independent prognostic factor. In conclusion, the proposed TME score model should be considered as a prognostic factor, similar to the current TNM stage, and the seven immune-related genes can be a valuable potential biomarker for breast cancer.

Aberrantly expressed Wnt5a in nurse-like cells drives resistance to Venetoclax in chronic lymphocytic leukemia.

Chronic lymphocytic leukemia (CLL) is characterized by the accumulation of neoplastic B lymphocytes with high levels of Wnt5a in the plasma. Currently, the cell source of Wnt5a remains controversial. The receptor of Wnt5a is ROR1, whose expression is associated with disease progression and resistance to venetoclax, a BCL-2 inhibitor approved for the treatment of CLL. In this study, we found that the levels of Wnt5a in the plasma of CLL patients were positively correlated with absolute monocyte counts, but not lymphocyte counts. We cultured monocyte-derived nurse-like cells (NLCs) from patients with CLL, and detected Wnt5a expressed in NLCs. Flow cytometry and transwell assays showed that the antibody neutralizing Wnt5a inhibited the enhanced survival and migration in CLL cells co-cultured with NLCs. Furthermore, we performed a drug screening with CLL cells cultured with or without NLCs with a library containing 133 FDA-approved oncology drugs by using high-throughput flow cytometry. We observed a significant resistance to venetoclax in CLL cells co-cultured with NLCs. Immunoblot revealed the activation of NF-κB with enhanced expression of MCL-1 and BCL-XL in CLL cells co-cultured with NLCs. Neutralizing Wnt5a or blocking NF-κB pathway significantly decreased the expression of MCL-1 and BCL-XL, which leads to enhanced sensitivity to venetoclax in CLL cells co-cultured with NLCs. In conclusion, our data showed that NLCs could be one of the sources of Wnt5a detected in patients with CLL, and Wnt5a-induced NF-κB activation in the CLL microenvironment results in resistance to venetoclax in CLL cells.

Nde1 is a Rab9 effector for loading late endosomes to cytoplasmic dynein motor complex.

Rab9 is mainly located on late endosomes and required for their intracellular transport to trans-Golgi network (TGN). The cytoplasmic dynein motor, together with its regulatory proteins Nde1/Ndel1 and Lis1, controls intracellular retrograde transport of membranous organelles along the microtubule network. How late endosomes are tethered to the microtubule-based motor dynein for their retrograde transport remains unclear. Here, we demonstrate that the guanosine triphosphate (GTP)-bound Rab9A/B specifically uses Nde1/Ndel1 as an effector to interact with the dynein motor complex. We determined the crystal structure of Rab9A-GTP in complex with the Rab9-binding region of Nde1. The functional roles of key residues involved in the Rab9A-Nde1 interaction are verified using biochemical and cell biology assays. Rab9A mutants unable to bind to Nde1 also failed to associate with dynein, Lis1, and dynactin. Therefore, Nde1 is a Rab9 effector that tethers Rab9-associated late endosomes to the dynein motor for their retrograde transport to the TGN.

PIAS3/SOCS1-STAT3 axis responses to oxidative stress in hepatocellular cancer cells.

The participation of STAT3 and its upstream inhibitors, PIAS3 and SOCS1, in the oxidative response of hepatocellular carcinoma (HCC) cells was uncertain. Here, the expression of PIAS3 and SOCS1 in HCC tissues and cell lines was explored, and we sought to determine whether oxidative stress epigenetically regulated PIAS3 and SOCS1 expression and STAT3 activation in HCC cells. The expression of PIAS3 and SOCS1 was markedly decreased in HCC cell lines and tissues compared to normal hepatic cells and tissues. In HCC patients, low PIAS3 and SOCS1 expression were associated with poor survival. Oxidative stress induced by H2O2 in HepG2 cells was indicated by low antioxidant levels and high protein carbonyl content. Moreover, oxidative stress in HepG2 cells contributed to reduced proliferation but increased apoptosis, migration, and invasion capacity, which might be counteracted by antioxidants, such as tocopheryl acetate (TA). PIAS3 and SOCS1 expression was markedly decreased, while STAT3 was activated in HepG2 cells in response to H2O2 exposure. Co-treatment with antioxidant TA effectively increased the expression of PIAS3 and SOCS1, but it dephosphorylated STAT3 in H2O2-treated cells. PIAS1 or SOCS1 overexpression in HepG2 cells after H2O2 treatment restored cell viability and anti-oxidative responses and decreased apoptosis, migration, and invasion ability, and dephosphorylated STAT3 levels. Co-administration of the STAT3 activator, colivelin, partially abolished the effect of PIAS3 and SOCS1 overexpression in these processes. Therefore, oxidative stress in HCC cells may improve their migration and reduce proliferation through STAT3 activation through the repression of PIAS3 and SOCS1 expression.

Virulence effector SidJ evolution in Legionella pneumophila is driven by positive selection and intragenic recombination.

Effector proteins translocated by the Dot/Icm type IV secretion system determine the virulence of Legionella pneumophila (L. pneumophila). Among these effectors, members of the SidE family (SidEs) regulate several cellular processes through a unique phosphoribosyl ubiquitination mechanism mediated by another effector, SidJ. Host-cell calmodulin (CaM) activates SidJ to glutamylate the SidEs of ubiquitin (Ub) ligases and to make a balanced Ub ligase activity. Given the central role of SidJ in this regulatory process, studying the nature of evolution of sidJ is important to understand the virulence of L. pneumophila and the interaction between the bacteria and its hosts. By studying sidJ from a large number of L. pneumophila strains and using various molecular evolution algorithms, we demonstrated that intragenic recombination drove the evolution of sidJ and contributed to sidJ diversification. Additionally, we showed that four codons of sidJ which are located in the N-terminal (NTD) (codons 58 and 200) and C-terminal (CTD) (codons 868 and 869) domains, but not in the kinase domain (KD) had been subjected to strong positive selection pressure, and variable mutation profiles of these codons were identified. Protein structural modeling of SidJ provided possible explanations for these mutations. Codons 868 and 869 mutations might engage in regulating the interactions of SidJ with CaM through hydrogen bonds and affect the CaM docking to SidJ. Mutation in codon 58 of SidJ might affect the distribution of main-chain atoms that are associated with the interaction with CaM. In contrast, mutations in codon 200 might influence the α-helix stability in the NTD. These mutations might be important to balance Ub ligase activity for different L. pneumophila hosts. This study first reported that intragenic recombination and positive Darwinian selection both shaped the genetic plasticity of sidJ, contributing to a deeper understanding of the adaptive mechanisms of this intracellular bacterium to different hosts.

Phase separation of EML4-ALK in firing downstream signaling and promoting lung tumorigenesis.

EML4-ALK fusion, observed in about 3%-7% of human lung adenocarcinoma, is one of the most important oncogenic drivers in initiating lung tumorigenesis. However, it still remains largely unknown about how EML4-ALK fusion exactly fires downstream signaling and drives lung cancer formation. We here find that EML4-ALK variant 1 (exon 1-13 of EML4 fused to exon 20-29 of ALK) forms condensates via phase separation in the cytoplasm of various human cancer cell lines. Using two genetically engineered mouse models (GEMMs), we find that EML4-ALK variant 1 can drive lung tumorigenesis and these murine tumors, as well as primary tumor-derived organoids, clearly show the condensates of EML4-ALK protein, further supporting the findings from in vitro study. Mutation of multiple aromatic residues in EML4 region significantly impairs the phase separation of EML4-ALK and dampens the activation of the downstream signaling pathways, especially the STAT3 phosphorylation. Importantly, it also significantly decreases cancer malignant transformation and tumor formation. These data together highlight an important role of phase separation in orchestrating EML4-ALK signaling and promoting tumorigenesis, which might provide new clues for the development of clinical therapeutic strategies in treating lung cancer patients with the EML4-ALK fusion.

Development of a highly sensitive method for detection of FLT3D835Y.

BACKGROUND: Acute myeloid leukemia (AML) is a malignant hematological neoplasm of myeloid progenitor cells. Mutations of FLT3 in its tyrosine kinase domain (FLT3-TKD) are found in ~ 8% of patients with AML, with D835Y as the most common substitution. This mutation activates survival signals that drives the disease and is resistant to the first generation FLT3 inhibitors. Development of a highly sensitive method to detect FLT3D835Y is important to direct therapeutic options, predict prognosis, and monitor minimal residual disease in patients with AML. METHODS AND RESULTS: In the present study, we developed a highly sensitive FLT3D835Y detection method by using the restriction fragment nested allele-specific PCR technique. The method consists of three steps: 1) initial amplification of DNA samples with PCR primers surrounding the FLT3D835Y mutation site, 2) digestion of the PCR products with restriction enzyme EcoRV that only cleaves the wild type allele, and 3) detection of FLT3D835Y by allele-specific PCR with nested primers. We were able to detect FLT3D835Y with a sensitivity of 0.001% by using purified plasmid DNAs and blood cell DNAs containing known proportions of FLT3D835Y. We analyzed blood cell DNA samples from 64 patients with AML and found six FLT3D835Y-positive cases, two of which could not be detected by conventional DNA sequencing methods. Importantly, the method was able to detect FLT3D835Y in a sample collected from a relapsed patient while the patient was in complete remission with negative MRD determined by flow cytometry. Therefore, our RFN-AS-PCR detected MRD after treatment that was missed by flow cytometry and Sanger DNA sequencing, by conventional methods. CONCLUSIONS: We have developed a simple and highly sensitive method that will allow for detection of FLT3D835Y at a very low level. This method may have major clinical implications for treatment of AML.

Highly improved soot combustion performance over synergetic MnxCe1-xO2 solid solutions within mesoporous nanosheets.

Constructing synergetic bimetal oxide solid solutions with exceptional catalytic performances for efficient soot elimination is becoming a research frontier in environmental catalysis. Herein, synergetic MnxCe1-xO2 solid solutions within mesoporous nanosheets, synthesized by a facile hydrothermal method for the first time, have been performed to catalyze the NOx-assisted soot combustion. Research results validate that MnxCe1-xO2 solid solutions displayed highly improved soot combustion performance with respect to activity and selectivity, mainly due to the synergetic effect by combining factors of the unique mesoporous nanosheet-shaped feature, the enhanced chemical nature stemmed from high-valence Mn species, abundant active oxygen species originated from the enriched oxygen vacancies and the escalated redox properties. Furthermore, the enhanced NOx storage and oxidation abilities, mainly derived from integrating reciprocal merits of high-valence Mn species and CeO2, were also responsible for the highly improved soot combustion performance via NOx-assisted mechanism. Moreover, MnxCe1-xO2 solid solutions also exhibited excellent reusability due to the unique morphological structure and stable crystal phase, showing good potential in practical applications.