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Many cancers harbor homologous recombination defects (HRDs). A HRD is a therapeutic target that is being successfully utilized in treatment of breast/ovarian cancer via synthetic lethality. However, canonical HRD caused by BRCAness mutations do not prevail in liver cancer. Here we report a subtype of HRD caused by the perturbation of a proteasome variant (CDW19S) in hepatitis B virus-bearing (HBV-bearing) cells. This amalgamate protein complex contained the 19S proteasome decorated with [CRL4.sup.WDR70] ubiquitin ligase, and assembled at broken chromatin in a [PSMD4.sup.Rpn10]-and ATM-MDC1-RNF8-dependent manner. CDW19S promoted DNA end processing via segregated modules that promote nuclease activities of MRE11 and EXO1. Contrarily, a proteasomal component, [ADRM1.sup.Rpn13], inhibited resection and was removed by [CRL4WDR.sup.70]-catalyzed ubiquitination upon commitment of extensive resection. HBx interfered with [ADRM1.sup.Rpn13] degradation, leading to the imposition of [ADRM1.sup.Rpn13]- dependent resection barrier and consequent viral HRD subtype distinguishable from that caused by BRCA1 defect. Finally, we demonstrated that viral HRD in HBV-associated hepatocellular carcinoma can be exploited to restrict tumor progression. Our work clarifies the underlying mechanism of a virus-induced HRD subtype., Introduction Long-term liver infection with hepatitis B virus (HBV) predisposes carriers to hepatocellular carcinoma (1). Therapy for late-stage HBV-associated hepatocellular carcinoma remains a major challenge, with poor therapy responses and [...]

Background Clinical observation suggests the atheroprotective effect of chloroquine and its derivatives, while its mechanism remains unclear. This study aimed to observe the protective effect of chloroquine against atherosclerosis and explore the underlying mechanism. Methods Ataxia telangiectasia mutated (ATM) wild-type or haploinsufficient apolipoprotein-E-knockout (ATM+/+ ApoE−/− or ATM+/− ApoE−/−) mice were treated with different dosages of chloroquine. Anti-CD25 antibody was used to deplete natural Tregs in ATM+/+ ApoE−/− mice. The atherosclerotic burden in different groups of mice was comprehensively evaluated by H&E staining and Masson staining. The effect of chloroquine on the regulatory T cells (Tregs) was assessed in vivo and in vitro by flow cytometry and immunohistochemical staining. The expression of related proteins was detected by real-time polymerase chain reaction and western blotting. Results In ATM+/+ ApoE−/− mice, chloroquine alleviated atherosclerotic lesions, stabilized the plaque, and increased Treg counts in the atherosclerotic lesions and spleens. However, in ATM haploinsufficient mice (ATM+/− ApoE−/−), chloroquine no longer prevented atherosclerosis or impacted Treg counts. Abolishing Treg cells using an anti-CD25 antibody in vivo abrogated the atheroprotective effect of chloroquine. In vitro, chloroquine promoted the differentiation of Tregs from naïve T cells, which was accompanied by enhanced ATM/AMP-activated protein kinase (AMPK) activity and reduced downstream mammalian target of rapamycin (mTOR) activity. Discussion These findings suggest that chloroquine ameliorates atherosclerosis and stabilizes plaque by modulating Tregs differentiation through the regulation of the ATM/AMPK/mTOR pathway. [ABSTRACT FROM AUTHOR]

Members of the Tre2-Bub2-Cdc16 (TBC) family often function to regulate membrane trafficking and to control signaling transductions pathways. As a member of the TBC family, TBC1D23 is critical for endosome-to-Golgi cargo trafficking by serving as a bridge between Golgi-bound golgin-97/245 and the WASH/FAM21 complex on endosomal vesicles. However, the exact mechanisms by which TBC1D23 regulates cargo transport are poorly understood. Here, we present the crystal structure of the N-terminus of TBC1D23 (D23N), which consists of both the TBC and rhodanese domains. We show that the rhodanese domain is unlikely to be an active sulfurtransferase or phosphatase, despite containing a putative catalytic site. Instead, it packs against the TBC domain and forms part of the platform to interact with golgin-97/245. Using the zebrafish model, we show that impacting golgin-97/245-binding, but not the putative catalytic site, impairs neuronal growth and brain development. Altogether, our studies provide structural and functional insights into an essential protein that is required for organelle-specific trafficking and brain development. The TBC1D23 protein functions in membrane trafficking and is critical for human neuronal development. The crystal structure of the N-terminus of TBC1D23 shows that its rhodanase domain is catalytically inactive and positioned close to the adjacent TBC domain, which together provide a binding interface for golgin-97/245. This interaction is essential for neuronal growth and brain development in zebrafish. [ABSTRACT FROM AUTHOR]

Angiogenesis and inflammation are crucial processes through which the tumor microenvironment (TME) influences tumor progression. In this study, we showed that peroxisome proliferator‐activated receptor γ (PPARγ) is not only expressed in CT26 and 4T1 tumor cell lines but also in cells of TME, including endothelial cells and tumor‐associated macrophages (TAM). In addition, we showed that rosiglitazone may induce tumor vessel normalization and reduce TAM infiltration. Additionally, 4T1 and CT26 tumor‐bearing mice treated with rosiglitazone in combination with radiotherapy showed a significant reduction in lesion size and lung metastasis. We reported that a single dose of 12 Gy irradiation strongly inhibits local tumor angiogenesis. Secretion of C‐C motif chemokine ligand 2 (CCL2) in response to local irradiation facilitates the recruitment of migrating CD11b+ myeloid monocytes and TAM to irradiated sites that initiate vasculogenesis and enable tumor recurrence after radiotherapy. We found that rosiglitazone partially decreases CCL2 secretion by tumor cells and reduces the infiltration of CD11b+ myeloid monocytes and TAM to irradiated tumors, thereby delaying tumor regrowth after radiotherapy. Therefore, combination of the PPARγ agonist rosiglitazone with radiotherapy enhances the effectiveness of radiotherapy to improve local tumor control, decrease distant metastasis risks and delay tumor recurrence. [ABSTRACT FROM AUTHOR]

In the previous study, we had showed the expression of CD133+ CD54+ CD44+ cellular subpopulation of circulating tumor cells ( CTCs) was significantly associated with liver metastasis of colorectal cancer ( CRC). This study aimed to explore whether this subpopulation of CTCs have a prognostic value in CRC patients. Flow cytometry was used to detect the expression of cellular subpopulations of CTCs with CD133, CD54, and CD44 in 152 CRC patients, between December 2013 and October 2014. The impact of clinicopathological factors and the expression of cellular subpopulations of CTCs on overall survival were then analyzed. CRC patients with liver metastases who underwent resection of the primary tumor accompanied by surgical treatment for metastasis had a better survival than other patients ( P < 0.001). The liver metastatic CRC patients with high expression of CD133+ CD54+ ( P < 0.001), CD133− CD54+ ( P = 0.004), and CD133+ CD44+ CD54+ ( P = 0.003) cellular subpopulations of CTCs had a worse survival than those patients with low expression. Multivariable survival analyses identified carcinoembryonic antigen levels (hazard ratio [ HR] = 3.056; 95% confidence interval [ CI] = 1.354-6.897; P = 0.007), treatment strategy ( HR = 0.212; 95% CI = 0.056-0.808; P = 0.023), and CD133+ CD44+ CD54+ cellular subpopulation of CTCs ( HR = 6.459; 95% CI = 1.461-28.558; P = 0.014) as independent prognostic factors for CRC patients with liver metastasis. CD133+ CD44+ CD54+ cellular subpopulation of CTCs has a prognostic value in CRC patients with liver metastasis, especially in the survival of CRC patients with liver metastasis who did not undergo surgical treatment for metastasis. [ABSTRACT FROM AUTHOR]

Tumor growth depends on the formation of blood vessels that provide the supply of nutrients and oxygen. Previous data have shown that glioblastoma stem cells are able to give rise to vascular cells to constitute the functional vessels in tumor tissues. However, which kinds of vascular cells are generated from glioblastoma stem cells is largely debated. In addition, there is little evidence showing that the stem cells from other kinds of tumors can produce vascular cells to constitute the functional blood vessels in tumor tissues. Here we show that cancer stem cells of human colorectal carcinomas (Co CSC) can give rise to vascular endothelial cells and compose the vasculatures in cancer tissues. The human-cell-specific nuclear antigen Nu MA+ vascular endothelial cells were detected in the blood vessels in xenografts derived from Co CSC. Nu MA+ endothelial cells incorporated into functional blood vessels. Our data indicate that the cancer stem cells derived from human colorectal carcinomas have the capacity to generate functional blood vessels and provide a new mechanism for tumor vasculogenesis in carcinoma. [ABSTRACT FROM AUTHOR]

Background/Aims: The aim of this study was to assess the association between circulating cell-derived microparticles (MPs) and type 2 diabetes mellitus (T2DM). Methods: A literature search was performed systematically in PubMed and Embase to identify available case-control or cross-sectional studies that compared different types of cell-derived MPs in patients with T2DM and non-diabetic controls. Pooled standardized mean differences (SMDs) of each MP type were pooled using meta-analysis. Results: Forty-eight studies involving 2,460 patients with T2DM and 1,880 non-diabetic controls were included for systematic review and 34 of which were included for quantitative study by meta-analysis. In the overall analysis, the levels of circulating total MPs (TMPs), platelet-derived MPs (PMPs), monocyte-derived MPs (MMPs) and endothelium-derived MPs (EMPs) were significantly higher in T2DM patients than those in controls (TMPs: SMD, 0.64; 95%CI, 0.12~1.15; P=0.02; PMPs: SMD, 1.19; 95%CI, 0.88~1.50; P <0.00001; MMPs: SMD, 0.92; 95%CI, 0.66~1.17; P <0.00001; EMPs: SMD, 0.73; 95%CI, 0.50~0.96; P <0.00001). Meanwhile, no significant difference was shown in leukocyte-derived MPs (LMPs) level between diabetic and non-diabetic groups (SMD, 0.37; 95%CI, -0.15~0.89; P=0.17). Conclusions: The counts of TMPs, PMPs, MMPs and EMPs elevated in patients with T2DM. And cell-derived MPs may play a role in the pathogenesis of T2DM. [ABSTRACT FROM AUTHOR]

Bone stromal cells are critical for bone homeostasis and regeneration. Growing evidence suggests that non-stem bone niche cells support bone homeostasis and regeneration via paracrine mechanisms, which remain to be elucidated. Here, we show that physiologically quiescent SM22α- lineage stromal cells expand after bone injury to regulate diverse processes of intramembranous bone regeneration. The majority of SM22α- lineage cells neither act as stem cells in vivo nor show their expression patterns. Dysfunction of SM22α- lineage niche cells induced by loss of platelet-derived growth factor receptor β (PDGFRβ) impairs bone repair. We further show that PDGFRβ-triggered hydrogen sulfide (H 2 S) generation in SM22α- lineage niche cells facilitates osteogenesis and angiogenesis and suppresses overactive osteoclastogenesis. Collectively, these data demonstrate that non-stem SM22α- lineage niche cells support the niche for bone regeneration with a PDGFRβ/H 2 S-dependent regulatory mechanism. Our findings provide further insight into non-stem bone stromal niche cell populations and niche-regulation strategy for bone repair. [Display omitted] • Non-stem SM22α- lineage niche cells are activated by injury to drive bone regeneration • Loss of PDGFRβ induces dysfunction of SM22α- lineage cells and then impairs bone repair • PDGFRβ, but not PDGFRα, is required for H 2 S production of SM22α- lineage niche cells • PDGFRβ-driven H 2 S production by SM22α- lineage cells regulates stem and progenitor cell fate Zhou et al. identify the distinct function of SM22α- lineage stromal cells in regulating diverse processes of intramembranous bone regeneration. These niche cells are activated upon injury and modulate stem and progenitor cell fate with a unique PDGFRβ/H 2 S-dependent regulatory mechanism. [ABSTRACT FROM AUTHOR]

Dopamine D1 receptor ( DRD1) gene is associated with the pathogenesis of myocardial infarction (MI) in aspects of plaque rupture, platelet aggregation, and neutrophil-mediated injury of cardiac myocytes. Thus, the study was designed to explore whether the A-48G polymorphism of the DRD1 gene was associated with MI. The genotype of the DRD1A-48G polymorphism was determined by polymerase chain reaction in the 602 Han Chinese participants, 255 MI patients and 347 controls without MI. A significant association was found between the A-48G polymorphism of DRD1 and MI (genotype model: χ2=13.2, unadjusted p=0.001; χ2=13.9, adjusted p=0.0002; dominant model: adjusted OR 2.05, 95%CI 1.40-3.00, p=0.0002; recessive model: adjusted OR 2.34, 95%CI 1.01-5.39, p=0.047). The G allele was a risk-increased allele for MI (unadjusted OR 1.83, 95%CI 1.34-2.50, p=0.0001; adjusted OR 1.94, 95%CI 1.40-2.68, p=0.00007). Thus, the study demonstrated the significant association between A-48G polymorphism of the DRD1 gene and MI. [ABSTRACT FROM AUTHOR]