Lanfang Li

Co-expression of PD-L1 and p-AKT is associated with poor prognosis in diffuse large B-cell lymphoma via PD-1/PD-L1 axis activating intracellular AKT/mTOR pathway in tumor cells

Programmed death-1 (PD-1) /programmed death-ligand 1 (PD-L1) engagement usually leads to diminished antitumor T-cell responses, which mediates the immune escape of tumor cells. However, little is known whether PD-1/PD-L1 could directly activates intracellular oncogenic signaling pathways in tumor cells. The purpose of this study is to investigate whether intracellular AKT/mTOR signaling could be directly activated by PD-1/PD-L1 during the malignant progression in diffuse large B-cell lymphoma (DLBCL). Detection of the expression of PD-L1 and p-AKT by immunohistochemistry (IHC) showed that both proteins were overexpressed in 54% and 48% DLBCL cases, respectively. Spearman test showed that PD-L1 expression was correlated with p-AKT expression (R=0.244, χ2=5.962; P=0.017) and the expression of PD-L1 and p-AKT were also correlated with clinic-pathological characteristics. In addition, survival analysis showed that DLBCL patients who co-expressed PD-L1 and p-AKT had significantly poorer outcome than patients with single positive or both negative expression (P<0.05). In vitro, total PD-L1 and membrane PD-L1 (mPD-L1) proteins were overexpressed in five DLBCL cell lines by western blot and flow cytometry. We observed that AKT/mTOR pathway was activated in DLBCL cells after stimulated with human recombination PD-1/Fc. Taken together, these results suggested that the combination of PD-1/PD-L1 antibodies and AKT/mTOR inhibitor might be a promising and novel therapeutic approach for DLBCL in the future.

miR-10a inhibits cell proliferation and promotes cell apoptosis by targeting BCL6 in diffuse large B-cell lymphoma

The BCL6 (B-Cell Lymphoma 6) gene is a proto-oncogene that is often expressed in diffuse large B-cell lymphomas (DLBCLs). BCL6 loss of function can kill DLBCL cells, demonstrating that BCL6 is necessary for the survival of DLBCL cells and could be a therapeutic target. In this study, we found that BCL6 protein levels were consistently upregulated in DLBCL tissues, whereas its mRNA levels varied randomly in tissues, suggesting that a post-transcriptional mechanism was involved in BCL6 regulation. We used bioinformatics analysis to search for miRNAs, which potentially target BCL6, and identified specific targeting sites for miR-10a in the 3′-untranslated region (3′-UTR) of BCL6. We further identified an inverse correlation between miR-10a levels and BCL6 protein levels, but not mRNA levels, in DLBCL tumor tissue samples. By overexpressing or knocking down miR-10a in DLBCL cells, we experimentally validated that miR-10a directly recognizes the 3′-UTR of the BCL6 transcript and regulated BCL6 expression. Furthermore, we demonstrated that negatively regulating BCL6 by miR-10a suppressed the proliferation and promoted apoptosis of DLBCL cells.

Upconverting and persistent luminescent nanocarriers for accurately imaging-guided photothermal therapy

The fluorescence-guided photothermal therapy (FPTT) has great potential in cancer treatment. However, the conventional FPTT has to be stimulated by external light, which tends to increase background noise and leads to the inaccurate infrared light irradiation for PTT. In this study, upconverting and persistent luminescent nanocarriers (UPLNs) loaded mesoporous silica nanoparticles (UPLNs@mSiO2) were first designed to solve the problem mentioned above. The UPLNs cores can effectively reduce the short-lived autofluorescence interference by exerting the delay time between signal acquisition and pulsed excitation light. For testing the luminescence properties, the indotcyanine green (ICG) as photothermal agent was encapsulated into the UPLNs@mSiO2. The experimental results showed that the UPLNs@mSiO2 nanoparticles could significantly reduce the short-lived autofluorescence interference and improve signal-to-noise ratio during FPTT. Our data suggest that UPLNs@mSiO2 may be a promising tool for improving the accuracy of PTT in vivo.

TPGS functionalized mesoporous silica nanoparticles for anticancer drug delivery to overcome multidrug resistance

Multidrug resistance (MDR) has become a very serious problem in cancer therapy. To effectively reverse MDR in tumor treatments, a new pH-sensitive nano drug delivery system (NDDS) composed of mesoporous silica nanoparticles (MSNs) and d-a-tocopheryl poly-ethylene glycol 1000 succinate (TPGS) copolymers was synthesized to deliver doxorubicin (DOX) into drug-resistant breast cancer cell line (MCF-7/ADR). DOX@MSNs-TPGS were characterized to have a single peak size distribution, high DOX loading efficiency and a pH-dependent drug release profile. MSNs-TPGS were internalized via caveolae, clathrin-mediated endocytosis and energy-dependent cellular uptake. The DOX@MSNs-TPGS exhibited 10-fold enhanced cell killing potency compared to free DOX and DOX@MSNs. The enhanced MDR reversal effect was ascribed to the higher amount of cellular uptake of DOX@MSNs-TPGS in MCF-7/ADR cells than that of free DOX and DOX@MSNs, as a result of the inhibition of P-gp mediated drug efflux by TPGS. In vivo studies of NDDS in tumor-bearing mice showed that DOX@MSNs-TPGS displayed better efficacy against MDR tumors in mice and reached the tumor site more effectively than DOX and DOX@MSNs, with minimal toxicity. These results suggest DOX@MSNs-TPGS developed in this study have promising applications to overcome drug resistance in tumor treatments.

Necroptosis as a potential therapeutic target in multiple organ dysfunction syndrome

Purpose To investigate how necroptosisis, i.e. programmed necrosis, is involved in MODS, and to examine whether Nec-1, a specific necroptosis inhibitor, ameliorates multiorgan injury in MODS. Experimental Design A model of MODS was established in six-week old SD rats using fracture trauma followed by hemorrhage. Control animals received sham surgery. Cell death form and necrosome formation were measured by fluorescence-activated cell sorting and western blotting. MODS rats were randomly assigned to receive Nec-1 or saline with pretreatment and once daily. The first end-point was 72 hours survival. Organ injury and dysfunction, inflammatory cytokine levels, and necroptotic execution protein expression were also recorded. Results Organ injury and dysfunction were significantly more severe in the MODS group than the sham group (all p<0.01). Furthermore, MODS-induced liver, lung and kidney tissue injury was characterized by necroptosis rather than apoptosis, and accompanied by necrosome formation. Compared to MODS group, Nec-1 administration significantly improved 72 hours survival (p<0.01). Nec-1 administration significantly reduced necroptosis-induced liver, lung and kidney injury and dysfunction, inhibited inflammatory cytokines production, inhibited release of necroptotic execution proteins such as high-mobility group box 1 and mixed-lineage kinase domain-like protein pseudokinase in MODS rats (all p<0.01). Conclusions These results suggest that necroptosis is involved the pathology of MODS. Further, a necroptotic inhibitor Nec-1 may be considered as an adjunct treatment for MODS.PURPOSE To investigate how necroptosisis, i.e. programmed necrosis, is involved in MODS, and to examine whether Nec-1, a specific necroptosis inhibitor, ameliorates multiorgan injury in MODS. EXPERIMENTAL DESIGN A model of MODS was established in six-week old SD rats using fracture trauma followed by hemorrhage. Control animals received sham surgery. Cell death form and necrosome formation were measured by fluorescence-activated cell sorting and western blotting. MODS rats were randomly assigned to receive Nec-1 or saline with pretreatment and once daily. The first end-point was 72 hours survival. Organ injury and dysfunction, inflammatory cytokine levels, and necroptotic execution protein expression were also recorded. RESULTS Organ injury and dysfunction were significantly more severe in the MODS group than the sham group (all p<0.01). Furthermore, MODS-induced liver, lung and kidney tissue injury was characterized by necroptosis rather than apoptosis, and accompanied by necrosome formation. Compared to MODS group, Nec-1 administration significantly improved 72 hours survival (p<0.01). Nec-1 administration significantly reduced necroptosis-induced liver, lung and kidney injury and dysfunction, inhibited inflammatory cytokines production, inhibited release of necroptotic execution proteins such as high-mobility group box 1 and mixed-lineage kinase domain-like protein pseudokinase in MODS rats (all p<0.01). CONCLUSIONS These results suggest that necroptosis is involved the pathology of MODS. Further, a necroptotic inhibitor Nec-1 may be considered as an adjunct treatment for MODS.