Arabidopsis NAC1 transduces auxin signal downstream of TIR1 to promote lateral root development

Auxin plays a key role in lateral root formation, but the signaling pathway for this process is poorly understood. We show here that NAC1, a new member of the NAC family, is induced by auxin and mediates auxin signaling to promote lateral root development. NAC1 is a transcription activator consisting of an N-terminal conserved NAC-domain that binds to DNA and a C-terminal activation domain. This factor activates the expression of two downstream auxin-responsive genes, DBP and AIR3. Transgenic plants expressing sense or antisense NAC1 cDNA show an increase or reduction of lateral roots, respectively. Finally, TIR1-induced lateral root development is blocked by expression of antisense NAC1 cDNA, and NAC1 overexpression can restore lateral root formation in the auxin-response mutant tir1, indicating that NAC1 acts downstream of TIR1.

The high-output nitric oxide pathway: role and regulation

Nitric oxide synthase (NOS) catalyzes the production of nitric oxide (NO), a short-lived radical gas with physiological or pathophysiological roles in nearly every organ system. The inducible NO synthase (iNOS) is a high-output isoform compared to the two constitutive NOSs. The iNOS from murine macrophages tightly binds calmodulin as a subunit, and its activity is not dependent on exogenous calmodulin or elevated calcium. This iNOS is induced at the transcriptional level by bacterial lipopolysaccharide (LPS) and interferon-gamma. The promoter region of the murine iNOS gene contains at least 24 oligonucleotide motifs corresponding to elements involved in the binding of transcription factors in the promoters of other cytokine-inducible genes. Nuclear factor NF-kappa B/c-rel, interacting with cycloheximide-sensitive protein(s) and binding to the NF-kappa Bd site in the iNOS promoter, controls the induction of iNOS by LPS. However, iNOS is also regulated posttranscriptionally. Complex regulation of iNOS at multiple levels may reflect the dual role of iNOS in host defense and autotoxicity.

Structure-activity relationships for a large diverse set of natural, synthetic, and environmental estrogens

Understanding structural requirements for a chemical to exhibit estrogen receptor (ER) binding has been important in various fields. This knowledge has been directly and indirectly applied to design drugs for human estrogen replacement therapy, and to identify estrogenic endocrine disruptors. This paper reports structure-activity relationships (SARs) based on a total of 230 chemicals, including both natural and xenoestrogens. Activities were generated using a validated ER competitive binding assay, which covers a 10(6)-fold range. This study is focused on identification of structural commonalities among diverse ER ligands. It provides an overall picture of how xenoestrogens structurally resemble endogenous 17beta-estradiol (E(2)) and the synthetic estrogen diethylstilbestrol (DES). On the basis of SAR analysis, five distinguishing criteria were found to be essential for xenoestrogen activity, using E(2) as a template: (1) H-bonding ability of the phenolic ring mimicking the 3-OH, (2) H-bond donor mimicking the17beta-OH and O-O distance between 3- and 17beta-OH, (3) precise steric hydrophobic centers mimicking steric 7alpha- and 11beta-substituents, (4) hydrophobicity, and (5) a ring structure. The 3-position H-bonding ability of phenols is a significant requirement for ER binding. This contributes as both a H-bond donor and acceptor, although predominantly as a donor. However, the 17beta-OH contributes as a H-bond donor only. The precise space (the size and orientation) of steric hydrophobic bulk groups is as important as a 17beta-OH. Where a direct comparison can be made, strong estrogens tend to be more hydrophobic. A rigid ring structure favors ER binding. The knowledge derived from this study is rationalized into a set of hierarchical rules that will be useful in guidance for identification of potential estrogens.

Hepatic arterial infusion of oxaliplatin plus fluorouracil/leucovorin vs. sorafenib for advanced hepatocellular carcinoma

BACKGROUND & AIMS

To compare the overall survival (OS) and disease progression free survival (PFS) in patients with advanced hepatocellular carcinoma (Ad-HCC) who are undergoing hepatic arterial infusion (HAI) of oxaliplatin, fluorouracil/leucovorin (FOLFOX) treatment vs. sorafenib.

METHODS

This retrospective study was approved by the ethical review committee, and informed consent was obtained from all patients before treatment. HAI of FOLFOX (HAIF) was recommended as an alternative treatment option for patients who refused sorafenib. Of the 412 patients with Ad-HCC (376 men and 36 women) between Jan 2012 to Dec 2015, 232 patients were treated with sorafenib; 180 patients were given HAIF therapy. The median age was 51 years (range, 16-82 years). Propensity-score matched estimates were used to reduce bias when evaluating survival. Survival curves were calculated by performing the Kaplan-Meier method and compared by using the log-rank test and Cox regression models.

RESULTS

The median PFS and OS in the HAIF group were significantly longer than those in the sorafenib group (PFS 7.1 vs. 3.3 months [RECIST]/7.4 vs. 3.6 months [mRECIST], respectively; OS 14.5 vs. 7.0 months; p <0.001 for each). In the propensity-score matched cohorts (147 pairs), both PFS and OS in the HAIF group were longer than those in the sorafenib group (p <0.001). At multivariate analysis, HAIF treatment was an independent factor for PFS (hazard ratio [HR] 0.389 [RECIST]/0.402 [mRECIST]; p <0.001 for each) and OS (HR 0.129; p <0.001).

CONCLUSION

HAIF therapy may improve survival compared to sorafenib in patients with Ad-HCC. A prospective randomized trial is ongoing to confirm this finding.

LAY SUMMARY

We compared the hepatic arterial infusion of FOLFOX (a combination chemotherapy) with sorafenib (a tyrosine kinase inhibitor) in patients with advanced hepatocellular carcinoma, retrospectively. It was found that hepatic arterial infusion of FOLFOX therapy may improve both progression free and overall survival in patients with advanced hepatocellular carcinoma.

Shorter durations and lower doses of peginterferon alfa-2a are associated with inferior hepatitis B e antigen seroconversion rates in hepatitis B virus genotypes B or C

As there is currently a lack of consensus on the most appropriate dose and duration of peginterferon alfa-2a (PEG-IFNα-2a) therapy in hepatitis B e antigen (HBeAg)-positive patients, the efficacy and safety of either 24 or 48 weeks' duration and 90 μg/week or 180 μg/week doses were compared. HBeAg-positive patients (n = 544; 34% genotype B, 51% genotype C) were randomized to receive PEG-IFNα-2a (2 × 2 factorial design) for 24 or 48 weeks and at 90 μg/week or 180 μg/week and included in the per-protocol population. The primary efficacy endpoint of the noninferiority study was HBeAg seroconversion 6 months posttreatment. The prespecified odds ratio (OR) noninferiority margin was 1.88 with a one-sided significance level of 0.025. The highest rates of HBeAg seroconversion 6 months posttreatment were in the 180/48 arm (36.2% versus 14.1%-25.8% in the other arms). When the dose and duration arms were pooled, the OR for noninferiority of 24 weeks versus 48 weeks was 2.17 (95% confidence interval [CI] 1.43, 3.31; P = 0.749) and for 90 μg versus 180 μg was 1.79 (95% CI 1.18, 2.72; P = 0.410). As the upper limit of the 95% CI of the ORs were >1.88, 24 weeks were inferior to 48 weeks and 90 μg/week was inferior to 180 μg/week. The highest rates of response in the 180/48 arm were achieved by patients with HBsAg <1,500 IU/mL at Week 12 (58%) or Week 24 (57%), whereas patients with HBsAg >20,000 IU/mL did not respond. Adverse events were typical of those associated with PEG-IFNα-2a.

CONCLUSION

Compared with lower doses and shorter durations, the licensed PEG-IFNα-2a treatment regimen (180 μg/48 weeks) was the most efficacious and beneficial for HBeAg-positive patients predominantly infected with hepatitis B virus genotypes B or C.

GRAB proteins, novel members of the NAC domain family, isolated by their interaction with a geminivirus protein

Geminiviruses encode a few proteins and depend on cellular factors to complete their replicative cycle. As a way to understand geminivirus-host interactions, we have searched for cellular proteins which interact with viral proteins. By using the yeast two-hybrid technology and the wheat dwarf geminivirus (WDV) RepA protein as a bait, we have isolated a family of proteins which we termed GRAB (for Geminivirus Rep A-binding). We report here the molecular characterization of two members, GRAB1 and GRAB2. We have found that the 37 C-terminal amino acids of RepA are required for interaction with GRAB proteins. This region contains residues conserved in an equivalent region of the RepA proteins encoded by other viruses of the WDV subgroup. The N-terminal domain of GRAB proteins is necessary and sufficient to interact with WDV RepA. GRAB proteins contain an unique acidic C-terminal domain while their N-terminal domain, of ca. 170 amino acids, are highly conserved in all of them. Interestingly, this conserved N-terminal domain of GRAB proteins exhibits a significant amino acid homology to the NAC domain present in proteins involved in plant development and senescence. GRAB1 and GRAB2 mRNAs are present in cultured cells and roots but are barely detectable in leaves. GRAB expression inhibits WDV DNA replication in cultured wheat cells. Our studies highlight the importance that the pathway(s) mediated by GRAB proteins, as well as by other NAC domain-containing proteins, might have on geminivirus DNA replication in connection to plant growth, development and senescence pathways.

IL-12 protects mice against pulmonary and disseminated infection caused by Cryptococcus neoformans

We examined the role of IL-12 in host resistance to Cryptococcus neoformans using a murine model of pulmonary and disseminated infection. In this model, mice were infected intratracheally with viable yeast cells. Mice untreated with IL-12 allowed an uncontrolled multiplication of yeast cells in the lung with infiltrations of few inflammatory cells, and a cryptococcal dissemination to the brain and meningitis by 3 weeks, resulting in death of all animals within 4-6 weeks. IL-12, when administered from the day of tracheal infection for 7 days, induced a marked infiltration of inflammatory cells, consisting mostly of mononuclear cells, and significantly reduced the number of viable yeast cells in the lung. The treatment suppressed brain dissemination, as shown by a marked reduction of yeast cells in the brain and prevention of meningitis. These effects resulted in a significant increase in the survival rate of infected mice. In contrast, late administration of IL-12 commencing on day 7 after instillation of yeast cells failed to protect the mice against infection with C. neoformans. In further experiments, early administration of IL-12 markedly induced interferon-gamma (IFN-gamma) mRNA in the lungs of infected mice, while no IFN-gamma mRNA was detected without this treatment. Our results indicate that IL-12 is effective when administered in the early period of pulmonary cryptococcal infection.

Dual Vascular Endothelial Growth Factor Receptor and Fibroblast Growth Factor Receptor Inhibition Elicits Antitumor Immunity and Enhances Programmed Cell Death-1 Checkpoint Blockade in Hepatocellular Carcinoma

BACKGROUND AND AIMS

Combining anti-angiogenic therapy with immune checkpoint blockade with anti-programmed cell death-1 (PD-1) antibodies is a promising treatment for hepatocellular carcinoma (HCC). Tyrosine kinase inhibitors are well-known anti-angiogenic agents and offer potential for combination with anti-PD-1 antibodies. This study investigated the possible underlying immunomodulatory mechanisms of combined therapy.

METHODS

HCC tissue samples for RNA-sequencing (RNA-seq) were obtained from patients with differential prognoses following anti-PD-1 treatment. Recombinant basic fibroblast growth factor (bFGF) and vascular endothelial growth factor A (VEGFA) were used to stimulate T cells following lenvatinib or sorafenib treatment, respectively. T cell function was analyzed by flow cytometry and lactate dehydrogenase assay. In vivo experiments were conducted in murine H22 and Hepa 1-6 competent models of HCC. Local immune infiltration in the tumor microenvironment (TME) was assessed using multicolor flow cytometry. Gene regulation was evaluated by RNA-seq. Microvascular density was measured by immunohistochemistry, and PD-1 ligand (PD-L1) induction was quantified by western blot.

RESULTS

The baseline expression of VEGF and fibroblast growth factor (FGF) in patients with progressive disease was significantly higher than in patients achieving stable disease following anti-PD-1 treatment. VEGFA and bFGF significantly upregulated the expression of PD-1, cytotoxic T-lymphocyte-associated protein-4, and Tim-3 on T cells, while inhibiting the secretion of interferon gamma (IFNG) and granzyme B and suppressing T cell cytotoxicity. This immunosuppressive effect was reverted by lenvatinib but not sorafenib. Furthermore, dual lenvatinib/anti-PD-1 antibody therapy led to better antitumor effects than either sorafenib or fibroblast growth factor receptor (FGFR) inhibitor (BGJ398) in H22 murine models of HCC. Combined lenvatinib/anti-PD-1 treatment also led to long-term immune memory formation, while synergistically modulating the TME and enhancing the cytotoxic effect of T cells. Finally, lenvatinib inhibited PD-L1 expression on human umbilical vein endothelial cells, which improved the function of T cells.

CONCLUSIONS

Inhibition of vascular endothelial growth factor receptor and FGFR augmented the efficacy of anti-PD-1 antibodies. Combined lenvatinib/anti-PD-1 treatment appears to exert antitumor activity by synergistically modulating effector T cell function in the TME and by mutually regulating tumor vessel normalization.

Identification and analysis of a retinoblastoma binding motif in the replication protein of a plant DNA virus: requirement for efficient viral DNA replication

Geminiviruses are plant DNA viruses with small genomes whose replication, except for the viral replication protein (Rep), depends on host proteins and, in this respect, are analogous to animal DNA tumor viruses, e.g. SV40. The mechanism by which these animal viruses create a cellular environment permissive for viral DNA replication involves the binding of a virally encoded oncoprotein, through its LXCXE motif, to the retinoblastoma protein (Rb). We have identified such a LXCXE motif in the Rep protein of wheat dwarf geminivirus (WDV) and we show its functional importance during viral DNA replication. Using a yeast two-hybrid system we have demonstrated that WDV Rep forms stable complexes with p130Rbr2, a member of the Rb family of proteins, and single amino acid changes within the LXCXE motif abolish the ability of WDV Rep to bind to p130Rbr2. The LXCXE motif is conserved in other members of the same geminivirus subgroup. The presence of an intact Rb binding motif is required for efficient WDV DNA replication in cultured wheat cells, strongly suggesting that one of the functions of WDV Rep may be the linking between viral and cellular DNA replication cycles. Our results point to the existence of a Rb-like protein(s) in plant cells playing regulatory roles during the cell cycle.

Canine parvovirus capsid structure, analyzed at 2.9 A resolution

The DNA-containing capsid of canine parvovirus (CPV) is analyzed following atomic refinement at 2.9 A resolution. The capsid contains 60 copies of the capsid protein related by icosahedral symmetry. The atomic model has been extended from the first residue (Gly37) of the unrefined 3.25 A structure towards the N terminus. The electron density shows that approximately 87% of the capsid proteins have N termini on the inside of the capsid, but for approximately 13%, the polypeptide starts on the outside and runs through one of the pores surrounding each 5-fold axis, explaining apparently conflicting antigenic data. Analysis of potential hydrogen bonds reveals approximately 50% more secondary structure than previously apparent. Most of the additional secondary structure are in the 71 and 221 residue-long loop insertions between beta-strands E and F and G and H, forming subunit-bridging sheets that likely add specificity to assembly interactions. Structural analysis of the extensive subunit interactions around the 3-fold axes shows that assembly is a multistep process with loops intertwining following initial contact. Estimated free energies of association suggest that the formation of 3 and 5-fold contacts likely takes precedence over 2-fold interactions. Energies for initial association into trimers or pentamers would be similar, but the intertwining of loops about the 3-fold axis adds an additional large activation barrier to dissociation. Analysis of the surfaces of the assembled capsid shows a surprising lack of basic amino acids that might have been expected to interact with the negatively charged phosphoribose backbone of the DNA. Instead, uncharged polar and van der Waal's interactions predominate in the packaging of single-stranded DNA into the capsid.

Aligning tumor mutational burden (TMB) quantification across diagnostic platforms: phase II of the Friends of Cancer Research TMB Harmonization Project

BACKGROUND

Tumor mutational burden (TMB) measurements aid in identifying patients who are likely to benefit from immunotherapy; however, there is empirical variability across panel assays and factors contributing to this variability have not been comprehensively investigated. Identifying sources of variability can help facilitate comparability across different panel assays, which may aid in broader adoption of panel assays and development of clinical applications.

MATERIALS AND METHODS

Twenty-nine tumor samples and 10 human-derived cell lines were processed and distributed to 16 laboratories; each used their own bioinformatics pipelines to calculate TMB and compare to whole exome results. Additionally, theoretical positive percent agreement (PPA) and negative percent agreement (NPA) of TMB were estimated. The impact of filtering pathogenic and germline variants on TMB estimates was assessed. Calibration curves specific to each panel assay were developed to facilitate translation of panel TMB values to whole exome sequencing (WES) TMB values.

RESULTS

Panel sizes >667 Kb are necessary to maintain adequate PPA and NPA for calling TMB high versus TMB low across the range of cut-offs used in practice. Failure to filter out pathogenic variants when estimating panel TMB resulted in overestimating TMB relative to WES for all assays. Filtering out potential germline variants at >0% population minor allele frequency resulted in the strongest correlation to WES TMB. Application of a calibration approach derived from The Cancer Genome Atlas data, tailored to each panel assay, reduced the spread of panel TMB values around the WES TMB as reflected in lower root mean squared error (RMSE) for 26/29 (90%) of the clinical samples.

CONCLUSIONS

Estimation of TMB varies across different panels, with panel size, gene content, and bioinformatics pipelines contributing to empirical variability. Statistical calibration can achieve more consistent results across panels and allows for comparison of TMB values across various panel assays. To promote reproducibility and comparability across assays, a software tool was developed and made publicly available.

Tumor-derived lactate inhibit the efficacy of lenvatinib through regulating PD-L1 expression on neutrophil in hepatocellular carcinoma

BACKGROUND

Neutrophils play a controversial role in tumor development. The function of programmed cell death-1 ligand (PD-L1⁺) neutrophils, however, may inhibit the cytotoxicity of anti-tumor immunity. In this study, we elucidate the stimulators of PD-L1⁺ neutrophils in tumor microenvironment (TME) and explore the optimal combination to enhance the effect of lenvatinib by inhibiting PD-L1⁺ neutrophils in hepatocellular carcinoma.

METHODS

Neutrophil infiltration after lenvatinib treatment was examined with RNA sequencing and multicolor flow cytometry analysis in patient samples, subcutaneous and orthotopic mouse models. Neutrophils and T cells were isolated from peripheral blood and tumor tissues and purified with magnetic beads for cytotoxicity assay. Metabolites and cytokines were detected by a biochemical analyzer manufactured by Yellow Springs Instrument (YSI) and proteome profiler cytokines array. In vitro screening of pathway inhibitors was used to identify possible candidates that could reduce PD-L1⁺ neutrophil infiltration. Further in vivo assays were used for verification.

RESULTS

Lenvatinib increased neutrophil recruitment by inducing CXCL2 and CXCL5 secretion in TME. After entering TME, neutrophils polarized toward N2 phenotype. PD-L1 expression was simultaneously upregulated. Thus, lenvatinib efficacy on tumor cells hindered. The increasing PD-L1⁺ neutrophils positively corelated with a suppressive T cell phenotype. Further investigation indicated that JAK/STAT1 pathway activated by immune-cell-derived interferon γ and MCT1/NF-kB/COX-2 pathway activated by high concentrations of tumor-derived lactate could induce PD-L1⁺ neutrophils. The latter could be significantly inhibited by COX-2 inhibitor celecoxib. Further in vivo assays verified that Celecoxib decreased the survival of lactate-stimulated PD-L1⁺ neutrophil and promoted the antitumor effect of lenvatinib.

CONCLUSIONS

PD-L1⁺ neutrophils decrease T cell cytotoxicity. Tumor-derived lactate induces PD-L1 expression on neutrophils via MCT1/NF-κB/COX-2 pathway. Thus, COX-2 inhibitor could reduce PD-L1⁺ neutrophil and restore T cell cytotoxicity. This may provide a potent addition to lenvatinib.

The maize retinoblastoma protein homologue ZmRb-1 is regulated during leaf development and displays conserved interactions with G1/S regulators and plant cyclin D (CycD) proteins

Recent discoveries of plant retinoblastoma (Rb) protein homologues and D-type cyclins suggest that control of the onset of cell division in plants may have stronger parallels with mammalian G1/S controls than with yeasts. In mammals, the Rb protein interacts specifically with D-type cyclins and regulates cell proliferation by binding and inhibiting E2F transcription factors. However, the developmental role of Rb in plants and its potential interaction with cell cycle regulators is unknown. We show that the maize Rb homologue ZmRb-1 is temporally and spatially regulated during maize leaf development. ZmRb-1 is highly expressed in differentiating cells, but almost undetectable in proliferating cells. In vitro, both ZmRb-1 and human Rb bind all classes of plant D-type cyclins with the involvement of a conserved N-terminal Leu-x-Cys-x-Glu (LxCxE) Rb-interaction motif. This binding is strongly reduced by mutation of the conserved Cys-470 of ZmRb-1. ZmRb-1 binds human and Drosophila E2F, and inhibits transcriptional activation of human E2F. We also show that ZmRb-1 is a good in vitro substrate for all human G1/S protein kinases. The functional conservation of proteins that control the G1/S transition in mammals and plants points to the existence of plant E2F homologues. We conclude that evolution of Rb and cyclin D proteins occurred after separation of the fungi from the higher eukaryotic lineage, but preceded the divergence of plant and animal kingdoms.

A novel antioxidant gene from Mycobacterium tuberculosis

Among the major antimicrobial products of macrophages are reactive intermediates of the oxidation of nitrogen (RNI) and the reduction of oxygen (ROI). Selection of recombinants in acidified nitrite led to the cloning of a novel gene, noxR1, from a pathogenic clinical isolate of Mycobacterium tuberculosis. Expression of noxR1 conferred upon Escherichia coli and Mycobacterium smegmatis enhanced ability to resist RNI and ROI, whether the bacteria were exposed to exogenous compounds in medium or to endogenous products in macrophages. These studies provide the first identification of an RNI resistance mechanism in mycobacteria, point to a new mechanism for resistance to ROI, and raise the possibility that inhibition of the noxR1 pathway might enhance the ability of macrophages to control tuberculosis.

Marek's disease virus (MDV) ICP4, pp38, and meq genes are involved in the maintenance of transformation of MDCC-MSB1 MDV-transformed lymphoblastoid cells

An antisense strategy has been used to identify genes important for the maintenance of transformation of MDCC-MSB1 (MSB1) Marek's disease virus-transformed lymphoblastoid cells. Oligodeoxynucleotides antisense to the predicted translation initiation regions of ICP4 and pp38 mRNAs inhibited proliferation of MSB1 cells but not MDCC-CU91 (CU91) reticuloendotheliosis virus-transformed cells. Control oligodeoxynucleotides having the same base composition but a different sequence did not inhibit MSB1 cell proliferation. In addition, ICP4 and pp38 antisense oligodeoxynucleotides resulted in 77- and 100-fold reductions in colony formation by MSB1 cells in soft agar, respectively. To extend and corroborate these results, a novel system based on efficiently regulated expression of eukaryotic genes by a chimeric mammalian transactivator, LAP267 (S. B. Baim, M. A. Labow, A. J. Levine, and T. Shenk, Proc. Natl. Acad. Sci. USA 88:5072-5076, 1991), was used. MSB1-derived stably transfected cell lines in which RNA antisense to Marek's disease virus ICP4, pp38, or meq could be induced by treatment of the cells with isopropyl-beta-D-thiogalactopyranoside (IPTG) were constructed. Control cell lines in which expression of ICP4 sense or pUC19 sequences could be induced by IPTG were also constructed. Induction of the cell lines indicated that ICP4 antisense RNA, but not ICP4 sense RNA or pUC19 RNA, inhibited proliferation of MSB1 cells. Induction of ICP4, meq, or pp38 antisense RNAs, but not ICP4 sense or pUC19 RNAs, had a dramatic effect on relative colony formation by MSB1 cells in soft agar. These results indicate that ICP4, pp38, and Meq are all involved in the maintenance of transformation of MSB1 cells.

The cloning of plant E2F, a retinoblastoma-binding protein, reveals unique and conserved features with animal G(1)/S regulators

Association of the retinoblastoma (Rb) protein with E2F transcription factors is central to cell cycle-specific gene expression and growth in animal cells. Whether Rb-E2F complexes are also involved in plant cell growth and differentiation is still unknown since E2F proteins have not yet been identified in plants. Here we report the isolation and characterisation of a wheat E2F (TmE2F) cDNA clone. Interestingly, the overall domain organisation of plant E2F is related to the human E2F-1/2/3 subset but its primary sequence is slightly more related to the E2F-4/5 subset. TmE2F-Rb binding depends on residues, located at the C-terminus, which are different from those of animal E2Fs. However, the acidic or hydrophobic nature of certain residues is maintained, strongly suggesting that they may have a crucial role in E2F activities. Plant E2F is expressed in proliferating cultured cells and in differentiated tissues and is up-regulated early in S phase. Our studies reinforce the idea that G(1)/S regulators in plants are unrelated to those of yeast cells but similar to those of animal cells and provide new tools to analyse the links between cell cycle regulators, plant growth and developmental signals.

The systemic immune-inflammation index is an independent predictor of survival for metastatic colorectal cancer and its association with the lymphocytic response to the tumor

BACKGROUND

Systemic inflammation and immune dysfunction has been proved to be significantly associated with cancer progression and metastasis in many cancer types, including colorectal cancer. We examined the prognostic significance of the systemic immune-inflammation index (SII) in patients with metastatic colorectal cancer (mCRC) and the relationship between the lymphocytic response to the tumor and this index.

METHODS

This retrospective study evaluated 240 consecutive patients with newly diagnosed stage IV mCRC who underwent surgical resection. The SII values were calculated based on preoperative laboratory data regarding platelet, neutrophil, and lymphocyte counts. Tumor-infiltrating lymphocytes were evaluated using the surgical specimens. The overall survival and their 95% confidence interval (95% CI) were estimated by regression analyses and the Kaplan-Meier method.

RESULTS

After a mean follow-up of 26.7 (1.1-92.4) months, 146 patients (60.8%) died. In the univariate analysis, a high SII was significantly associated with poor overall survival (P = 0.009). The multivariable analysis also confirmed that a high SII was independently associated with poor overall survival (hazard ratio: 1.462, 95% confidence interval 1.049-2.038, P = 0.025). The SII value was significantly correlated with the TILs value at the tumor's center (P = 0.04), but not at the invasive margin (P = 0.39). When we evaluated overall survival for groupings of the tumor-infiltrating lymphocytes and SII values, we identified three distinct prognostic groups. The group with low tumor-infiltrating lymphocyte values and high SII values had the worst prognosis.

CONCLUSIONS

A high SII value independently predicts poor clinical outcomes among patients with mCRC. In addition, combining the lymphocytic response to the tumor and SII could further enhance prognostication for mCRC.

Natural CD8+CD122+ T cells are more potent in suppression of allograft rejection than CD4+CD25+ regulatory T cells

Despite extensive studies on CD4+CD25+ regulatory T cells (Tregs), their application in adoptive transfer therapies is still not optimal in immune-competent wild-type (WT) animal models. Therefore, it is compelling to search for more potent Tregs for potential clinical application. Mounting evidence has shown that naturally occurring CD8+CD122+ T cells are also Tregs. However, their suppression in allograft rejection, efficiency in suppression and underlying mechanisms remain unclear. Using a murine allotransplantation model, we reported here that CD8+CD122+ Tregs were actually more potent in suppression of allograft rejection and underwent more rapid homeostatic proliferation than their CD4+CD25+ counterparts. Moreover, they produced more IL-10 and were more potent in suppressing T cell proliferation in vitro. Deficiency in IL-10 in CD4+CD25+ and CD8+CD122+ Tregs resulted in their reduced but equal suppression in vivo and in vitro, suggesting that IL-10 is responsible for more effective suppression by CD8+CD122+ than CD4+CD25+ Tregs. Importantly, transfer of CD8+CD122+ Tregs together with the administration of recombinant IL-15 significantly prolonged allograft survival in WT mice. Thus, for the first time, we demonstrate that naturally arising CD8+CD122+ Tregs not only inhibit allograft rejection but also exert this suppression more potently than their CD4+CD25+ counterparts. This novel finding may have important implications for tolerance induction.

Functional disconnection between the visual cortex and the sensorimotor cortex suggests a potential mechanism for self-disorder in schizophrenia

Self-disorder is a hallmark characteristic of schizophrenia. This deficit may stem from an inability to efficiently integrate multisensory bodily signals. Twenty-nine schizophrenia patients and thirty-one healthy controls underwent resting-state fMRI in this study. A data-driven method, functional connectivity density mapping (FCD), was used to investigate cortical functional connectivity changes in the patients. Areas with significantly different FCD were chosen to calculate functional connectivity maps. The schizophrenia patients exhibited increased local FCD in frontal areas while demonstrating decreased local FCD in the primary sensorimotor area and in the occipital lobe. The functional connectivity analysis illustrated decreased functional connectivity between visual areas and the primary sensorimotor area. These findings suggest disturbed integration in perception-motor processing, which may contribute to mapping the neural physiopathology associated with self-disorder in schizophrenia patients.

CLINICAL TRIAL REGISTRATION

Chinese Clinical Trial Registry. Registration number. ChiCTR-RCS-14004878.

Current status and recent advances of next generation sequencing techniques in immunological repertoire

To ward off a wide variety of pathogens, the human adaptive immune system harbors a vast array of T-cell receptors (TCRs) and B-cell receptors (BCRs), collectively referred to as the immune repertoire. High-throughput sequencing (HTS) of TCR/BCR genes allows in-depth molecular analysis of T/B-cell clones, providing an unprecedented level of detail when examining the T/B-cell repertoire of individuals. It can evaluate TCR/BCR complementarity-determining region 3 (CDR3) diversity and assess the clonal composition, including the size of the repertoire; similarities between repertoires; V(D)J segment use; nucleotide insertions and deletions; CDR3 lengths; and amino acid distributions along the CDR3s at sequence-level resolution. Deep sequencing of B-cell and T-cell repertoires offers the potential for a quantitative understanding of the adaptive immune system in healthy and disease states. Recently, paired sequencing strategies have also been developed, which can provide information about the identity of immune receptor pairs encoded by individual T or B lymphocytes. HTS technology provides a previously unimaginable amount of sequence data, accompanied, however, by numerous challenges associated with error correction and interpretation that remain to be solved. The review details some of the technologies and some of the recent achievements in this field.

Discovery of a series of nonpeptide small molecules that inhibit the binding of insulin-like growth factor (IGF) to IGF-binding proteins

Insulin-like growth factors (IGF-I and II) play an important role in metabolic and mitogenic activities through stimulation of the IGF-I receptor on the cell surface. Although the concentration of IGF in blood and cerebrospinal fluid is quite high (>100 nM), this large pool of IGF is biologically inactive because of its association with six distinct binding proteins, which form high-affinity complexes with IGF. Thus, inhibitors of IGF-binding proteins (IGFBPs), especially IGFBP-3, could potentially alter the distribution between the "free" and "bound" forms of IGF and thereby elevate biologically active IGF-I to exert a beneficial effect on those patients with diseases that respond to the application of exogenous IGF-I. Whereas IGF-I peptide variants, which bind to IGFBPs but not the IGF-I receptor, have been shown to be potent IGF/IGFBP inhibitors, small molecule nonpeptide IGF/IGFBP inhibitors have the potential advantages of oral bioavailability and flexible dosing regimen. Here we report the discovery of several isoquinoline analogues, exemplified by 1 and 2, which bind IGFBP-3 as well as other IGFBPs at low nanomolar concentrations. More importantly, both compounds were shown to be able to release biologically active IGF-I from the IGF-I/IGFBP-3 complex. These results point to the feasibility of developing orally active therapeutics to treat IGF-responsive diseases by optimization of the lead molecules 1 and 2.