Characteristics of mesenchymal stem cells and their exosomes derived from giant panda (Ailuropoda melanoleuca) endometrium.

Conservation of genetic resources is an important way to protect endangered species. At present, mesenchymal stem cells (MSCs) have been isolated from the bone marrow and umbilical cords of giant pandas. However, the types and quantities of preserved cell resources were rare and limited, and none of MSCs was derived from female reproductive organs. Here, we first isolated MSCs from the endometrium of giant panda. These cells showed fibroblast morphology and expressed Sox2, Klf4, Thy1, CD73, CD105, CD44, CD49f, and CD105. Endometrium mesenchymal stem cells (eMSCs) of giant panda could induce differentiation into three germ layers in vitro. RNA-seq analysis showed that 833 genes were upregulated and 716 genes were downregulated in eMSCs compared with skin fibroblast cells. The results of GO and the KEGG analysis of differentially expressed genes (DEGs) were mainly focused on transporter activity, signal transducer activity, pathways regulating pluripotency of stem cells, MAPK signaling pathway, and PI3K-Akt signaling pathway. The genes PLCG2, FRK, JAK3, LYN, PIK3CB, JAK2, CBLB, and MET were identified as hub genes by PPI network analysis. In addition, the exosomes of eMSCs were also isolated and identified. The average diameter of exosomes was 74.26 ± 13.75 nm and highly expressed TSG101 and CD9 but did not express CALNEXIN. A total of 277 miRNAs were detected in the exosomes; the highest expression of miRNA was the has-miR-21-5p. A total of 14461 target genes of the whole miRNAs were predicted and proceeded with functional analysis. In conclusion, we successfully isolated and characterized the giant panda eMSCs and their exosomes, and analyzed their functions through bioinformatics techniques. It not only enriched the conservation types of giant panda cell resources and promoted the protection of genetic diversity, but also laid a foundation for the application of eMSCs and exosomes in the disease treatment of giant pandas.

CENP-F-dependent DRP1 function regulates APC/C activity during oocyte meiosis I.

Chromosome segregation is initiated by cohesin degradation, which is driven by anaphase-promoting complex/cyclosome (APC/C). Chromosome cohesin is removed by activated separase, with the degradation of securin and cyclinB1. Dynamin-related protein 1 (DRP1), a component of the mitochondrial fission machinery, is related to cyclin dynamics in mitosis progression. Here, we show that DRP1 is recruited to the kinetochore by centromeric Centromere protein F (CENP-F) after nuclear envelope breakdown in mouse oocytes. Loss of DRP1 during prometaphase leads to premature cohesin degradation and chromosome segregation. Importantly, acute DRP1 depletion activates separase by initiating cyclinB1 and securin degradation during the metaphase-to-anaphase transition. Finally, we demonstrate that DRP1 is bound to APC2 to restrain the E3 ligase activity of APC/C. In conclusion, DRP1 is a CENP-F-dependent atypical spindle assembly checkpoint (SAC) protein that modulates metaphase-to-anaphase transition by controlling APC/C activity during meiosis I in oocytes.

Comparison of transcriptome profiles of mesenchymal stem cells derived from umbilical cord and bone marrow of giant panda (Ailuropoda melanoleuca).

Mesenchymal stem cells (MSCs) have pluripotent differentiation ability and play an important role in human clinical cell therapy. While, the research on MSCs in endangered wild animals is extremely rare. In our previous studies, the bone marrow mesenchymal stem cells (bmMSCs) and umbilical cord mesenchymal stem cells (ucMSCs) of giant panda (Ailuropoda melanoleuca) were successfully isolated. We aimed to characterize the differences in gene expression profiles between these two types of MSCs using RNA sequencing (RNA-Seq) and to determine which potential pathways are involved in functional regulation. In total, 1079 significantly differentially expressed genes (DEGs) were identified, of which 478 genes were upregulated and 601 genes were downregulated. The significantly enriched Gene Ontology (GO) terms mainly contained cell adhesion, biological adhesion, intracellular signal transduction, molecular function regulator, Ras protein signal transduction, small GTPase mediated signal transduction, and regulation of Rho protein signal transduction. The most enrichment pathways of DEGs enriched in Kyoto Encyclopedia of Genes Genomes (KEGG) were PI3K-AKT signaling pathway, Rap1 signaling pathway, MAPK signaling pathway, Hippo signaling pathway, Wnt signaling pathway, cGMP-PKG signaling pathway and Signaling pathways regulating pluripotency of stem cells. In addition, quantitative real time polymerase chain reaction (qRT-PCR) showed that the AKT3, CDK2, MAPK3, mTOR, PI3K and PTK2 genes associated with PI3K-AKT pathway were highly expressed (P < 0.01), and Caspase-3 was low expressed (P < 0.05) in ucMSCs group when compared with bmMSCs. After treatment with the PI3K inhibitor LY294002, genes AKT3, CDK2, MAPK3, mTOR, and PTK2 were significantly decreased in ucMSCs (P < 0.01), and Caspase-3 was significantly up regulated (P < 0.001). In conclusion, we for the first time compared and analyzed the transcriptome profiles of giant panda ucMSCs and bmMSCs, and found the PI3K-AKT pathway was highly activated and might be a key signaling pathway in the ucMSCs regulation. This study will be beneficial for the research on MSCs proliferation regulation and differentiation of giant pandas in the future, and lay the foundation for MSCs application and clinical therapy for endangered wild animals.

A unique self-reporting photosensitizer enabling simultaneous photodynamic therapy and real-time monitoring of phototheranostic process in a dynamic dual-color mode.

Phototheranostics has attracted great interest in cancer therapy. Small-molecule self-reporting photosensitizers, one kind of idea agent in phototheranostics, enables simultaneous photodynamic therapy (PDT) and feedback of therapeutic efficacy. However, previous such photosensitizers exclusively employed the change of single emission to monitor cell death, which can be disturbed by variations in photosensitizer concentration and the excitation intensity. Herein, we report a unique self-reporting photosensitizer TPA-3PyA+ constructed from a twisted triphenylamine unit (TPA), three benzene ring units and three cyanovinyl-pyridinium units (PyA) for PDT and its real-time monitoring in a dynamic dual-color mode. TPA-3PyA+ possesses a rotatable electron donor-π bridge-electron acceptor framework and exhibits high singlet oxygen quantum yield (124%) and a twisted intramolecular charge transfer (TICT) effect. TPA-3PyA+ not only enables effective staining of cancer cells with dual-color fluorescence due to the TICT effect but also shows excellent PDT performance. The simultaneous change in emission color, intensity and intracellular location of TPA-3PyA+ during cell death allows it to self-report cell death. Moreover, the change of dual-emission color allows distinguishing living and dead cells and effectively avoids interference in previous single-emission self-reporting photosensitizers. This work highlights the great potential of a self-reporting photosensitizer with dual-color emissions for efficient feedback of theranostics.

Enhancing near-infrared AIE of photosensitizer with twisted intramolecular charge transfer characteristics via rotor effect for AIE imaging-guided photodynamic ablation of cancer cells.

Near-infrared (NIR) aggregation-induced emission (AIE) of previous organic photosensitizers is usually weak because of the competition between twisted intramolecular charge transfer (TICT) effect and AIE. Herein, we report a rational molecular design strategy to boost NIR AIE of photosensitizers and still to keep strong 1O2 production capacity via rotor effect. To this end, one new triphenylamine (TPA)-based AIE photosensitizer, TPAM-1, is designed to give strong ability to generate 1O2 but weak NIR fluorescence in the aggregate state due to the strong TICT effect. Another new TPA-based AIE photosensitizer, TPAM-2, is designed by introducing three p-methoxyphenyl units as rotors into the structure of TPAM-1 to modulate the competition between AIE and TICT. TPAM-1 and TPAM-2 exhibit stronger ability to generate 1O2 in the aggregate state than the commercial photosensitizer, Ce6. Furthermore, TPAM-2 gives much brighter NIR luminescence (25-times higher quantum yield) than TPAM-1 in the aggregate state due to the rotor effect. TPAM-2 with strong NIR AIE and 1O2 production capability was encapsulated by DSPE-PEG2000 to give good biocompatibility. The DSPE-PEG2000-encapsulated TPAM-2 nanoparticles show good cell imaging performance and remarkable photosensitive activity for killing HeLa cells. This work provides a new way for designing ideal photosensitizers for AIE imaging-guided photodynamic therapy.

Prognostic influence of prevertebral space involvement in nasopharyngeal carcinoma: A retrospective study.

PURPOSE: To evaluate how prevertebral space involvement (PSI) and degree of tumor extension within the space affects prognosis in nasopharyngeal carcinoma (NPC). PARTICIPANTS AND METHODS: Data of patients with newly-diagnosed nonmetastatic NPC (n = 757) were retrospectively analyzed. Patients were separated into groups according to presence or absence of PSI and degree of tumor spread. Overall survival (OS), failure-free survival (FFS), local relapse-free survival (LRFS), and distant metastasis-free survival (DMFS) were compared between the groups. RESULTS: Prevalence of PSI, simple prevertebral muscle involvement (PMI), and behind prevertebral muscle involvement (BPMI) were 44.9% (340/757), 22.5% (170/757), and 22.5% (170/757), respectively. OS, FFS, LRFS, and DMFS for patients with and without PSI were 64% vs. 84.8%, 68% vs. 85.6%, 85.8% vs. 94.4%, and 78.5% vs. 92.8%, respectively (all P < 0.001). PSI was an independent predictor of OS, FFS, LRFS, and DMFS. OS, FFS, and DMFS for patients with simple PMI and with BPMI were 72.7% vs. 54.8% (P = 0.002), 75.8% vs. 59.8% (P = 0.003), and 85.5% vs. 71.2% (P = 0.002), respectively. Degree of PSI extension was related to OS, FFS, and DMFS. OS, FFS, LRFS, and DMFS were significantly poorer in patients with PSI in T2-3 stage than in patients without PSI in T3 stage (P < 0.05), but comparable to those in patients with T4 stage (P > 0.05). CONCLUSIONS: PSI predicts poor prognosis in NPC. Survival is poorer in patients with BPMI than in those with simple PMI. NPC with PSI should be classified as T4 stage.

Influence of tumor necrosis on treatment sensitivity and long-term survival in nasopharyngeal carcinoma.

PURPOSE: To assess the impact of tumor necrosis on treatment sensitivity and long-term survival in patients with nasopharyngeal carcinoma (NPC) treated using intensity-modulated radiation therapy (IMRT). PARTICIPANTS AND METHODS: In total, 757 patients with non-metastatic, histologically confirmed NPC were retrospectively examined. All patients were treated using IMRT; 93.7% patients with stage T3-T4/N1-N3 disease also received cisplatin-based chemotherapy. RESULTS: The incidence rates of tumor necrosis in primary tumor, retropharyngeal lymph nodes, neck lymph nodes, and total tumor were 2%, 17.7%, 21.5%, and 31.4%. Overall, 40.8% patients with necrosis of the total tumor achieved complete response (CR) and 54.7% patients without tumor necrosis achieved CR at the end of treatment (χ2 = 12.728, P < 0.001). The estimated 7-year overall survival (OS), failure-free survival (FFS), distant metastasis-free survival (DMFS), and loco-regional relapse-free survival (LRRFS) for patients with tumor necrosis and without tumor necrosis of the total tumor were 68.5% vs. 88.4%, 70.5% vs. 88.1%, 77.6% vs. 90.6%, and 85.9% vs. 91.3%, respectively (all P < 0.001). Multivariate analyses indicated that necrosis of the total tumor was an independent predictor of OS, FFS, DMFS, and LRRFS. The impact of lymph node necrosis on long-term survival was similar to that of necrosis of the total tumor. ROC curves verified that inclusion of lymph node necrosis improved the predictive value of the current N classification criteria (P = 0.006). CONCLUSIONS: Tumor necrosis served as a predictor of treatment sensitivity and poor prognosis for patients with NPC. Lymph node necrosis significantly improved the prognostic value of the current N classification criteria for NPC.

Development of a Uricase-Free Colorimetric Biosensor for Uric Acid Based on PPy-Coated Polyoxometalate-Encapsulated Fourfold Helical Metal-Organic Frameworks.

Developing a new cost-effective and reliable approach used for the detection of uric acid (UA) with no requirement of uricase is still very challenging. Herein, an easily realized, cost-effective, and uricase-free approach is reported for selective colorimetric biosensing of UA utilizing polypyrrole (PPy)-coated polyoxometalate-encapsulated fourfold helical metal-organic frameworks Ag5[bimt]2[PMo12O40]·2H2O (Ag5PMo12) as a monolithic peroxidase mimic. It is demonstrated that the as-obtained Ag5PMo12@PPy possesses excellent peroxidase-like activity originated from the synergistic effect to induce catalytic oxidation of colorless 3,3',5,5'-tetramethylbenzidine (TMB) to green oxTMB in the presence of H2O2. Then, the green oxTMB can be selectively converted to colorless TMB induced by UA; thus, UA can inhibit the catalytic oxidation of TMB. Based on these results, a uricase-free colorimetric biosensor for UA is achieved with a linear detection range of 1-50 µM and a detection limit of 0.47 µM. More importantly, the developed biosensor is suited for simple-operated and good reliable UA detection in clinical samples, showing promising application ability in clinical diagnosis and relative fields.

[Effect of different courses of electroacupuncture intervention on recognition memory and proliferation and differentiation of hippocampal neural stem cells in mice with radiation-induced brain injury].

OBJECTIVE: To observe the influence of different courses of electroacupuncture (EA) intervention on recognition memory and the proliferation and differentiation of hippocampal neural stem cells in mice with radiation-induced brain injury, so as to explore its mechanisms underlying improving radiation-induced brain injury. METHODS: Se-venty 30-day old C57BL/6J mice were randomly divided into control, model and EA groups, and the latter two groups were further divided into 1 week (W), 2 W and 3 W subgroups (n=10 in the control group and each subgroup). The ra-diation-induced brain injury model was established by radiating the mouse' left head at a dose of 8 Gy for 10 min by using a radiation linear accelerator. EA (1.5 V, 2 Hz/10 Hz) was applied to "Baihui" (GV20), "Fengfu" (GV14) and bilateral "Shenshu" (BL23) for 30 min, once daily for 1, 2 and 3 weeks, respectively. The learning-cognition memory ability was detected by using novel object recognition test in an open test box to record the time for exploring a novel object (TN) and a familiar object and to calculate the recognition index (RI). The neural stem cells' proliferation and differentiation in the hippocampus tissues were evaluated by counting the number of bromodeoxyuridine (BrdU)-labeled cells, neuronal nuclei (NeuN)/BrdU-positive cells and BrdU/glia fibrillary acidic protein (GFAP)-positive cells under microscope after immunofluorescence stain. RESULTS: After modeling, the TN at 90 min and 24 h and RI of the model subgroup 3 W at 90 min and RI of the model subgroup 1, 2 and 3 W at 24 h were significantly decreased in comparison with those of the control group (P<0.01, P<0.05). Moreover, the number of BrdU-positive cells in the model subgroup 1 W and 2 W, the BrdU/NeuN double-labeled cells in the 3 model subgroups and BrdU/GFAP double-labeled cells in the model subgroup 1 W and 3 W were significantly decreased (P<0.01, P<0.05). Following EA interventions, the TN in the 3 EA subgroups at both 90 min and 24 h, and RI of EA subgroup 3 W at 90 min and EA subgroup 2 W and 3 W at 24 h were considerably increased compared with those of the corresponding 3 model subgroups (P<0.05, P<0.01). The numbers of BrdU-positive cells as well as BrdU/NeuN and BrdU/GFAP double-labeled cells were significantly increased in the 3 EA subgroups (P<0.05, P<0.01, P<0.001). CONCLUSION: EA of GV20, GV14 and BL23 can improve the recognition memory ability of mice with radiation-induced brain injury, which may be related to its effect in promoting the proliferation and differentiation of stem cells in the hippocampus.

Sodium nitrite negatively affects reproductive ability and offspring survival in female mice.

Sodium nitrite (NaNO2) is an industrial chemical that is frequently used as a food additive to prevent botulism and enhance glossiness, such as curing meat. In addition, in some regions, water source NaNO2 concentrations exceed standard regulatory levels. Whether the excessive intake of NaNO2 has toxic effects on female fertility and fetal development remain unknown. In this study, we administered ICR mice control saline, low-dose NaNO2 (60 mg/kg/day), or high-dose NaNO2 (120 mg/kg/day) by intragastric gavage for 21 days. We then assessed oocyte morphology, spindle-chromosome dynamics, mitochondrial distribution, ATP content, apoptotic cell numbers, DNA damage levels, histone modifications, reactive oxygen species (ROS) levels, and offspring survival. Results showed that NaNO2 treatment decreased oocyte number, impaired polar body extrusion, and increased zona pellucida thickness in oocytes. Furthermore, NaNO2 disrupted MII spindle integrity, caused abnormal mitochondrial distribution, decreased ATP content, and increased levels of ROS and H3K4me2. Moreover, the number of oocytes in early stages of apoptosis and with levels of DNA damage increased in NaNO2-treated mice along with decreased offspring numbers and survival rates. We demonstrated the negative effects of NaNO2 on female reproductive abilities in mice.

Targeted upregulation of uncoupling protein 2 within the basal ganglia output structure ameliorates dyskinesia after severe liver failure.

Impaired motor function, due to the dysfunction of the basal ganglia, is the most common syndrome of hepatic encephalopathy (HE), and its etiology remains poorly understood. Neural oxidative stress is shown to be the major cellular defects contributing to HE pathogenesis. Mitochondrial uncoupling protein 2 (UCP2) has been implicated in neuroprotection in several neurological disorders. We explored the neuroprotective role of UCP2 within the substantia nigra pars reticulate (SNr), the output structure of the basal ganglia, in HE. The toxin thioacetamide (TAA) induced HE mice showed hypolocomotion, which was associated with decreased ATP levels and loss of antioxidant substances SOD and GSH within the SNr. Stable overexpression of UCP2 via AAV-UCP2 under the control of the UCP2 promoter in bilateral SNr preserved local ATP level, increased antioxidant substances, and ameliorated locomotion defects after severe liver failure. Contrary to UCP2 overexpression, targeted knockdown of UCP2 within bilateral SNr via AAV-UCP2 shRNA exacerbated the impaired mitochondrial dysfunction and hypokinesia in HE mice. The modulatory effects of UCP2 was due to mediation of K+-Cl- cotransporter-2 (KCC2) expression on GABAergic neurons of SNr. Taken together, our results demonstrate that UCP2 exerts a neural protective role at the subcortical level by increasing the resistance of neurons to oxidative stress, which may offer a novel therapeutic target for the treatment of motor dysfunction diseases.

Glial cell line-derived neurotrophic factor supplementation promotes bovine in vitro oocyte maturation and early embryo development.

Paracrine factors such as glial cell line-derived neurotrophic factor (GDNF), which was originally derived from the supernatants of a rat glioma cell line, play pivotal roles in oocyte maturation and early embryo development in mammals, such as mice, rats, pigs, sheep, and even humans. However, whether GDNF facilitates in vitro oocyte maturation or early embryo development in bovines is not yet known. We show for the first time that GDNF and its receptor, GDNF family receptor alpha-1 (GFRA1), are presented in ovarian follicles at different stages as well as during oocyte maturation and early embryo development. Immunostaining results revealed the subcellular localizations of GDNF and GFRA1 in oocytes throughout follicle development, first in germinal vesicles and during blastocyst embryo stages. The ability of exogenously applied GDNF to promote oocyte maturation and early embryo development was evaluated in culture, where we found that an optimal concentration of 50 ng/mL promotes the maturation of cumulus-oocyte complexes and the nuclei of denuded oocytes as well as the development of embryos after IVF. To further investigate the potential mechanism by which GDNF promotes oocyte maturation, bovine oocytes were treated with morpholinos targeting Gfra1. The suppression of GFRA1 presence blocked endogenous and exogenous GDNF functions, indicating that the effects of GDNF that are essential and beneficial for bovine oocyte maturation and early embryo development occur through this receptor. Furthermore, we show that supplementation with GDNF improves the efficiency of bovine IVF embryo production.

Lentiviral Vectors and Adeno-Associated Virus Vectors: Useful Tools for Gene Transfer in Pain Research.

Pain, especially chronic pain, has always been a heated point in both basic and clinical researches since it puts heavy burdens on both individuals and the whole society. A better understanding of the role of biological molecules and various ionic channels involved in pain can shed light on the mechanism under pain and advocate the development of pain management. Using viral vectors to transfer specific genes at targeted sites is a promising method for both research and clinical applications. Lentiviral vectors and adeno-associated virus (AAV) vectors which allow stable and long-term expression of transgene in non-dividing cells are widely applied in pain research. In this review, we thoroughly outline the structure, category, advantages and disadvantages and the delivery methods of lentiviral and AAV vectors. The methods through which lentiviral and AAV vectors are delivered to targeted sites are closely related with the sites, level and period of transgene expression. Focus is placed on the various delivery methods applied to deliver vectors to spinal cord and dorsal root ganglion both of which play important roles in primary nociception. Our goal is to provide insight into the features of these two viral vectors and which administration approach can be chosen for different pain researches. Anat Rec, 301:825-836, 2018. © 2017 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.

Loss of function of KIF1B impairs oocyte meiotic maturation and early embryonic development in mice.

Kinesin family member 1B (KIF1B) is an important microtubule-dependent monomeric motor in mammals, although little is known about its role in meiosis. We profiled KIF1B expression and localization during oocyte maturation and early embryonic development in mice, revealing a dynamic pattern throughout meiotic progression. Depletion or inhibition of KIF1B leads to abnormal polar body extrusion, disordered spindle dynamics, defects in chromosome congression, increased aneuploidy, and impaired embryonic development. Further, KIF1B depletion affects the distribution of mitochondria and abundance of ATP. Taken together, our study demonstrates that mouse KIF1B is important for spindle assembly, chromosome congression, and mitochondrial distribution during oocyte maturation and early embryonic development. Mol. Reprod. Dev. 83: 1027-1040, 2016 © 2016 Wiley Periodicals, Inc.

Study on the mesothelin-specific cytotoxicity against epithelial ovarian cancer with full-length mesothelin cDNA-transduced dendritic cells.

Epithelial ovarian cancer (EOC) has the highest mortality rate among the various types of gynecological cancers. As the current therapeutic approaches are not enough, the development of more effective treatments to improve the survival of patients with EOC is urgently needed. Mesothelin (MSLN) is a cell surface glycoprotein, which is overexpressed in ovarian cancer tissues. As an immunotherapeutic approach, in this study, we investigated whether the genetically modified dendritic cells (DCs) expressing MSLN could induce cytotoxic T lymphocytes (CTLs) to produce MSLN-specific cytotoxic activity against EOCs. Here, we report that DCs transfected with full-length coding sequence of MSLN could induce MSLN-specific CTLs responses against ovarian cancer lines SKOV3 and OVCAR3 in vitro. Additionally, we identified that the death rates of ovarian cancer cells, killed by MSLN-specific CTLs, were significantly higher than the normal CTLs. Furthermore, IFN-γ production by stimulated MSLN-specific CTLs was significantly higher than that of unstimulated CTLs. This study showed that induced CTLs by DCs with full-length MSLN cDNA have effective immune response against the ovarian cancer cells, indicating that MSLN-transfected DCs vaccine has a promising prospect for the treatment of EOC.

Egg consumption is associated with increased risk of ovarian cancer: Evidence from a meta-analysis of observational studies.

BACKGROUND: The findings of epidemiologic studies on the association between egg consumption and ovarian cancer risk remain conflicting. The aim of this meta-analysis was to investigate whether an association exists between egg intake and ovarian cancer risk in epidemiologic studies. METHODS: A literature search was carried out using PUBMED, EMBASE, and Cochrane Library Central database for all medical literature published in English-language journals up to August 2013. Before meta-analysis, between-study heterogeneity and publication bias were assessed using adequate statistical tests. Fixed-effect and random-effect models were used to estimate summary relative risks (RR) and the corresponding 95% confidence intervals (CIs). Subgroup analyses and sensitivity analysis were also performed. RESULTS: A total of 12 eligible studies (six case-control studies and six cohort studies) were included, involving 629,453 subjects and 3728 ovarian cancer cases. We found that high egg intake (comparing the highest with the lowest category) was associated with a significant increased risk of ovarian cancer (RR = 1.21, 95% CI [1.06, 1.38]). When we examined whether the associations differed by study type, statistically significant effect of egg intake on ovarian cancer was observed among case-control studies (RR = 1.22, 95% CI [1.03, 1.43]), but not among cohort studies (RR = 1.20, 95% CI [0.97, 1.48]). CONCLUSIONS: Our findings suggest that egg consumption may increase ovarian cancer risk. Additional studies, especially large prospective cohort studies, are warranted to confirm the findings.

Checkpoint inhibitors in immunotherapy of ovarian cancer.

The treatment of ovarian cancer is a major challenge in oncology as mortality from ovarian cancer remains very high. The immune system plays a critical role in controlling cancer through a dynamic relationship with cancer cells. Immunotherapy can establish a sustained immune system response against recurring cancer cells leading to long-term remissions for ovarian cancer patient. The use of immune checkpoint inhibitors, which work by targeting molecules that serve as checks and balances in the regulation of immune responses, might be a promising avenue of immunotherapeutic research in ovarian cancer. In this review, we have focused on the potential of certain immune checkpoint inhibitors, such as anti-cytotoxic T lymphocyte antigens, anti-programmed death agents, and anti-program death ligands against ovarian cancer, with their mechanism of actions. Also, the problems arising due to checkpoint inhibitor immunotherapy have been discussed in this review. Checkpoint inhibitor immunotherapy is still in early-phase testing for ovarian cancer. Understanding the pivotal role of the tumor microenvironment in suppressing anticancer immunity, the unique adverse effects profiles of these agents, and the exploration of combinatorial treatment regimens will ultimately lead to enhance the efficacy of ovarian cancer immunotherapies and improved patient care.

Characterization of an ethylene-inducible, calcium-dependent nuclease that is differentially expressed in cucumber flower development.

• Production of unisexual flowers is an important mechanism that promotes cross-pollination in angiosperms. We previously identified primordial anther-specific DNA damage and organ-specific ethylene perception responsible for the arrest of stamen development in female flowers, but little is known about how the two processes are linked. • To identify potential links between the two processes, we performed suppression subtractive hybridization (SSH) on cucumber (Cucumis sativus L.) stamens of male and female flowers at stage 6, with stamens at stage 5 of bisexual flowers as a control. • Among the differentially expressed genes, we identified an expressed sequence tag (EST) encoding a cucumber homolog to an Arabidopsis calcium-dependent nuclease (CAN), designated CsCaN. Full-length CsCaN cDNA and the respective genomic DNA sequence were cloned and characterized. The CsCaN protein exhibited calcium-dependent nuclease activity. CsCaN showed ubiquitous expression; however, increased gene expression was detected in the stamens of stage 6 female flowers compared with male flowers. As expected, CsCaN expression was ethylene inducible. It was of great interest that CsCaN was post-translationally modified. • This study demonstrated that CsCaN is a novel cucumber nuclease gene, whose DNase activity is regulated at multiple levels, and which could be involved in the primordial anther-specific DNA damage of developing female cucumber flowers.

Why is ethylene involved in selective promotion of female flower development in cucumber?

Our recent work by Wang et al (2010), together with previous studies published in the last decade, have provided evidence suggesting a link between ethylene signaling and primordial anther specific DNA damage in female cucumber flowers. These findings explained ethylene promotion of female flower by ethylene inhibition of stamen development. However, it is not determined if ethylene promotes carpel development. In addition, an explanation of why the naturally occurring gas ethylene was selected to be involved in such developmental events remains elusive. In this study, we carried out a phylogenetic analysis of cucumber ACS genes, and analyzed the expression levels of some pre-miRNAs in male, female and hermaphrodite flowers. We found the M gene might have evolved prior to, or "co-opted" into unisexual flower development before the F gene, and miRNA might be involved in carpel development regulation. Based on these observations, we propose a new hypothesis to explain why ethylene was selected to be involved in the evolution of the unisexual cucumber flower.