A single-cell survey of cellular hierarchy in acute myeloid leukemia.

BACKGROUND: Acute myeloid leukemia (AML) is a fatal hematopoietic malignancy and has a prognosis that varies with its genetic complexity. However, there has been no appropriate integrative analysis on the hierarchy of different AML subtypes. METHODS: Using Microwell-seq, a high-throughput single-cell mRNA sequencing platform, we analyzed the cellular hierarchy of bone marrow samples from 40 patients and 3 healthy donors. We also used single-cell single-molecule real-time (SMRT) sequencing to investigate the clonal heterogeneity of AML cells. RESULTS: From the integrative analysis of 191727 AML cells, we established a single-cell AML landscape and identified an AML progenitor cell cluster with novel AML markers. Patients with ribosomal protein high progenitor cells had a low remission rate. We deduced two types of AML with diverse clinical outcomes. We traced mitochondrial mutations in the AML landscape by combining Microwell-seq with SMRT sequencing. We propose the existence of a phenotypic "cancer attractor" that might help to define a common phenotype for AML progenitor cells. Finally, we explored the potential drug targets by making comparisons between the AML landscape and the Human Cell Landscape. CONCLUSIONS: We identified a key AML progenitor cell cluster. A high ribosomal protein gene level indicates the poor prognosis. We deduced two types of AML and explored the potential drug targets. Our results suggest the existence of a cancer attractor.

Construction of a human cell landscape at single-cell level.

Single-cell analysis is a valuable tool for dissecting cellular heterogeneity in complex systems1. However, a comprehensive single-cell atlas has not been achieved for humans. Here we use single-cell mRNA sequencing to determine the cell-type composition of all major human organs and construct a scheme for the human cell landscape (HCL). We have uncovered a single-cell hierarchy for many tissues that have not been well characterized. We established a 'single-cell HCL analysis' pipeline that helps to define human cell identity. Finally, we performed a single-cell comparative analysis of landscapes from human and mouse to identify conserved genetic networks. We found that stem and progenitor cells exhibit strong transcriptomic stochasticity, whereas differentiated cells are more distinct. Our results provide a useful resource for the study of human biology.

The role of SOCS3 in the hypothalamic paraventricular nucleus in rat model of inflammatory pain.

BACKGROUND: Inflammatory molecular signals are modulated by a variety of intracellular transduction pathways, the activation of which may induce and amplify the spread of inflammatory response. Suppresser of cytokine signaling 3 (SOCS3) is an established negative feedback regulation transcription factor associated with tumor, diabetes mellitus, inflammation and anaphylaxis. Herein, we investigated whether SOCS3 in the paraventricular nucleus (PVN) can attenuate pro-inflammatory responses, and thereby relieve the inflammatory pain. METHODS: Adeno-associated virus (AAV) overexpressing SOCS3 was pre-injected into the PVN. Three weeks later, rat model of chronic inflammatory pain was established via subcutaneous injection of complete Freund's adjuvant (CFA) into the plantar center of hind paws. The therapeutic effect of SOCS3 was tested by the measurement of thermal and mechanical allodynia. In mechanistic study, the protein level of SOCS3 was evaluated by Western blotting, and the expression of c-fos and Iba-1 were assessed by immunofluorescent staining. RESULTS: Inflammatory pain was associated with upregulated interleukin 6 (IL-6) and SOCS3 in PVN in the acute phase. Thermal hyperalgesia can be relieved by intra-PVN injection of IL-6 neutralizing antibody (NA). Meanwhile, the upregulated c-fos and microglial activation was reversed. Furthermore, SOCS3 expression in PVN was downregulated in the chronic phase. Intra-PVN injection of AAV overexpressing SOCS3 suppressed the activation of neurons and attenuated thermal hyperalgesia and mechanical allodynia. CONCLUSION: Inhibition of IL-6 signaling attenuated inflammatory hyperalgesia in the acute phase. SOCS3 overexpression in the PVN attenuated inflammatory pain in the chronic phase via suppression of neuronal activation.

Water-soluble chiral CdSe/CdS dot/rod nanocrystals for two-photon fluorescence lifetime imaging and photodynamic therapy.

Compared with traditional organic contrast agents, semiconductor nanocrystals (NCs) have unique optical properties that are vital for biological applications with ultrahigh sensitivities, such as long fluorescence lifetime and large multiphoton absorption (MPA). However, the MPA properties and biological applications of chiral-ligand-stabilized semiconductor NCs have scarcely been reported, which seriously hinders their relevant applications. In this work, we report the aqueous phase transfer of CdSe/CdS dot/rod NCs with the use of cysteine molecules, after which the NCs preserve their high fluorescence quantum yield, long lifetime, and efficient circular dichroism. More importantly, the investigated dot/rod NCs show extremely large two- and three-photon absorption action cross-sections in the first and second biological windows, with maximum values of ∼21 000 GM at 800 nm and ∼4.6 × 10-78 cm6 s2 per photon2 at 1300 nm, which are among the largest values reported for water-soluble fluorescent nanoparticles. Interestingly, the dot/rod NCs exhibit a high singlet oxygen generation efficiency of 35%. In addition, for the first time, two-photon fluorescence lifetime imaging and photodynamic therapy of the dot/rod NCs were successfully demonstrated. The performed investigation of the optical properties of these water-soluble CdSe/CdS dot/rod NCs indicates that they are promising candidates for nonlinear biological imaging applications.

Clinical Significance of MRI and Pathological Features of Giant Cell Tumor of Bone Boundary.

OBJECTIVE: To find new clues to reduce postoperative recurrence after intralesional curettage by studying MRI and pathological features of giant tumor of bone (GCTB) boundaries. METHODS: A retrospective study was performed in the departments of orthopaedic surgery and medical imaging at our hospitals from January 2006 to August 2016. A total of 16 GCTB patients confirmed by pathology were asked to participate in the present study. The age range was from 18 to 44 years (9 women and 7 men). All patients underwent MRI examination. All patients underwent en bloc resection and complete postoperative tumor segments were obtained. Five specimens were obtained randomly at the place of the segments where the GCTB boundary showed different types on MRI. Ordinary HE staining was used for all specimens and we measured the depth of local tumor cell infiltration (240 measurements). Results were expressed as means ± standard deviation. Statistical analyses were carried out with one-way ANOVA and the Student-Newman-Keuls test. P < 0.05 was considered statistically significant. The kappa test was used to analyze the degree of agreement of observers. RESULTS: A total of 16 patients (median age 30.56 years; range, 18-44 years) with GCTB (the number of distal femurs and proximal tibias was 9 and 7, respectively) were tested. The boundaries of all GCTB cases were composed of clear boundary, relatively clear boundary, and blurred boundary in different proportions on MRI. Based on continuous observation of all MRI, all boundaries were incomplete. The kappa value between two radiologists and two pathologists was 0.91 and 0.88, respectively. The average depth of local tumor cell infiltration in the clear boundary, relatively clear boundary, and blurred boundary groups was 0.42 ± 0.11 mm, 2.85 ± 0.21 mm, and 4.83 ± 0.12 mm, respectively. There was statistical difference among the three groups (F = 17.62, P < 0.05). There was also statistical difference between each of the two groups (q-value was 8.95, 14.28, and 5.21, respectively, P < 0.05). The depth of local tumor cell infiltration with blurred boundaries on MRI was the largest and the depth with clear boundaries was the smallest. CONCLUSION: The intralesional curettage boundaries need to be expanded on the basis of different types of boundaries provided by MRI.

Capillary electrophoresis-chemiluminescence detection for carcino-embryonic antigen based on aptamer/graphene oxide structure.

A new strategy is proposed for determination of carcino-embryonic antigen (CEA) based on aptamer/graphene oxide (Apt/GO) by capillary electrophoresis-chemiluminescence (CE-CL) detection system. CEA aptamer conjugated with horseradish peroxidase (HRP) firstly mixes with GO, and the CL will be quenched because the stack of HRP-Apt on GO leads to chemiluminescence resonance energy transfer (CRET). When CEA exists, the specific combination of HRP-Apt and CEA can form HRP-Apt-CEA complex, which dissociates from GO. Then, the CL catalyzed by HRP-Apt-CEA complex can be detected without any CRET, and the content of CEA can be estimated by the CL intensity. It has been proved that the interference issue resulted from free HRP-Apt is solved well by mixing GO firstly with HRP-Apt, which blocks the free HRP-Apt's CL signal due to CL quenching effect of GO; and the interference resulted from GO to CL is also solved by CE, then the sensitivity and accuracy can be greatly improved. Results also showed that the CL intensity had a linear relationship with the concentration of CEA in the range from 0.0654 to 6.54 ng/mL, and the limit of detection was approximately 4.8 pg/mL (S/N = 3). This proposed method with high specificity offers a new way for separation and determination of biomolecule, and has good potential in application of biochemistry and bioanalysis.

Carcino-embryonic antigen detection based on fluorescence resonance energy transfer between quantum dots and graphene oxide.

The mixture of graphene oxide (GO) and aptamer labeled fluorophore is widely used in developing fluorescent sensors for the analysis of biomolecules, according to the light signal 'off-on' procedure. Moreover, the laser-induced fluorescence-coupled affinity probe capillary electrophoresis (APCE) technique has been broadly applied for the separation of micromolecules. Here, a strategy is proposed for analysis of content of carcino-embryonic antigen (CEA) based on the combination of GO and quantum dots labeling aptamer (QD-aptamer) by capillary electrophoresis (CE). The method has three advantages: (i) combined with CE, only few samples are required and efficiency of separation is high, (ii) fluorescent detection can be carried out after separation of GO and fluorescence probe combined with targets by CE, while fluorescence detection sensitivity had been greatly improved, and (iii) the issues of APCE, including the effect of excess fluorescence probe and maximizing separation between analytes, could be solved by introducing GO. It has been proved that QD-aptamer-CEA complex can completely dissociate from GO. Results show that the fluorescence intensity has a linear relationship with the concentration of CEA in the range from 0.257 to 12.9 ng/mL, and the limit of detection is approximately 5 pg/mL (S/N=3). The proposed method with high specificity has been applied for the accurate analysis of content of CEA in patient׳s serum.

A new strategy for the detection of adenosine triphosphate by aptamer/quantum dot biosensor based on chemiluminescence resonance energy transfer.

We designed an aptasensor for the detection of adenosine triphosphate (ATP) based on chemiluminescence resonance energy transfer (CRET). An adenosine aptamer was cut into two pieces of ssDNA, which were attached to quantum dots (QDs) and horse radish peroxidase (HRP), respectively. They could reassemble into specific structures in the presence of ATP and then decrease the distance of HRP and QDs. ATP detection can be easily realized according to the fluorescent intensity of QDs, which is excited by CRET between luminol and QDs. Results show that the concentration of ATP is linear relation with the fluorescent intensity of the peak of QDs emission and the linear range for the linear equation is from 50 µM to 231 µM and the detection limit was 185 nM. When the concentration of ATP was 2 mM, the efficiency of CRET is 13.6%. Good specificity for ATP had been demonstrated compared to thymidine triphosphate (TTP), cytidine triphosphate (CTP) and guanosine triphosphate (GTP), when 1 mM of each was added, respectively. This method needs no external light source and can avoid autofluorescence and photobleaching, and ATP can be detected selectively, specifically, and sensitively in a low micromolar range, which means that the strategy reported here can be applicable to the detection of several other target molecules.

Relationship between traditional Chinese medicine syndrome differentiation and imaging characterization to the radiosensitivity of nasopharyngeal carcinoma.

BACKGROUND AND OBJECTIVE: Traditional Chinese medicine (TCM) is a well established and time-honored practice in China, employing syndrome differentiation as a basis for the treatment of disease. According to different TCM syndrome typing findings, combining modern medical methods with TCM approaches can improve the quality of life and comprehensive effect on patients with nasopharyngeal carcinoma (NPC). This study investigated the relationship between TCM syndrome typing and imaging characterization to radiosensitivity as to provide objective evidence for the integration of Chinese and modern medical approaches in the treatment of NPC. METHODS: Prior to treatment, TCM syndrome typing, computed tomography (CT) and magnetic resonance imaging (MRI) were performed on 147 patients pathologically classified with NPC. The status of tumor remission was radiologically evaluated at accumulated doses of 20 Gy, 40 Gy and 60 Gy, and at 3 months after completion of radiotherapy. Statistical results were analyzed by the Friedman and K-W test procedures. RESULTS: Prior to treatment, TCM syndrome typing of NPC included Lung Heat, Blood Stasis, Phlegm Congealment and Blood Stasis-Phlegm Congealment. Lung Heat typing accounted for the highest proportion at 34.7% (51/147), followed by Phlegm Congealment at 32.7% (48/147), Blood Stasis at 17.0% (25/147) and Blood Stasis-Phlegm Congealment at 15.7% (23/147). Radiological imaging demonstrated a higher incidence of cervical lymph node metastases in Phlegm Congealment and Blood Stasis-Phlegm Congealment types (P<0.05), while Blood Stasis and Blood Stasis-Phlegm Congealment types were more prone to skull base invasion (P<0.05). Residual tumor size was larger in Blood Stasis and Blood Stasis-Phlegm Congealment types than in Lung Heat and Phlegm Congealment types after 3 months of treatment (P<0.05). CONCLUSIONS: Different radiological manifestations were observed in TCM syndrome typed NPC patients, with lesser radiosensitivity demonstrated in the Blood Stasis and the Blood Stasis-Phlegm Congealment types relative to the Lung Heat and Phlegm Congealment types.

Synthesis and antitumor activity of novel 2',3'-dideoxy-2',3'-diethanethionucleosides bearing 1,2,3-triazole residues.

A series of novel 2',3'-dideoxy-2',3'-diethanethioribonucleosides and those modified with a triazole ring were prepared in excellent yields and their antitumor activity was evaluated. Nucleosides with a triazole ring, 16a-16c, showed significantly improved activity towards a broad range of tumor cell lines.