Synergistic Inhibition of Thalidomide and Icotinib on Human Non-Small Cell Lung Carcinomas Through ERK and AKT Signaling.

BACKGROUND Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) have been widely used in the treatment of non-small cell lung cancer (NSCLC) patients with sensitive EGFR mutations. However, the survival of patients with EGFR-TKI administration is limited by the inevitable development of acquired drug resistance. Recently, multi-targeted drugs combination has been shown to be a promising strategy to improve the efficacy of EGFR-TKI treatment and enable the reduction of drug resistance in NSCLC. MATERIAL AND METHODS Humanized NSCLC cell lines PC9 and A549 were co-cultured with thalidomide and/or icotinib to test for anti-tumor efficiency. Cell proliferation was measured by MTT assay, cell apoptosis by flow cytometry and cell migration by wound healing assay. Western blot was performed to determine the expression of caspase-3, -8, -9, Bax, EGFR, VEGF-R, AKT, ERK, MMP2, MMP9, and NF-κB. The xenograft mouse model was used to explore the effects of thalidomide and icotinib in vivo. Immunohistochemical testing was used to determine the expression of Ki-67 and TUNEL staining in tumor tissues. RESULTS Treatments of thalidomide and/or icotinib reduced cell viability, induced apoptosis, and suppressed migration. Attenuation of pEGFR and pVEGF-R resulted in deactivation of ERK and AKT pathways, which eventually increased the anti-proliferative response. In PC9 xenograft model, combined administration of thalidomide and icotinib restrained tumor growth with remarkable reduced Ki-67 index and increased TUNEL positive cells. CONCLUSIONS Thalidomide sensitizes icotinib to increase apoptosis and prevent migration, and it may be a potentially promising anti-tumor drug in lung cancer multi-modality therapy.

Antitumor effector B cells directly kill tumor cells via the Fas/FasL pathway and are regulated by IL-10.

We have previously reported that adoptive transfer of tumor-draining lymph node (TDLN) B cells confers tumor regression in a spontaneous pulmonary metastasis mouse model of breast cancer. In this study, we identified IL-10-producing cells within these B cells, and found that IL-10 removal, either by using IL-10(-/-) TDLN B cells or by systemic neutralization of IL-10, significantly augmented the therapeutic efficacy of adoptively transferred TDLN B cells. Depletion of IL-10 in B-cell adoptive transfers significantly increased CTLs and B-cell activity of PBMCs and splenic cells in the recipient. Activated TDLN B cells express Fas ligand, which was further enhanced by coculture of these TDLN B cells with 4T1 tumor cells. Effector B cells killed tumor cells directly in vitro in an antigen specific and Fas ligand-dependent manner. Trafficking of TDLN B cells in vivo suggested that they were recruited to the tumor and lung as well as secondary lymphoid organs. These findings further define the biological function of antitumor effector B cells, which may offer alternative cellular therapies to cancer.

Thioridazine Sensitizes Esophageal Carcinoma Cell Lines to Radiotherapy-Induced Apoptosis In Vitro and In Vivo.

BACKGROUND Radiotherapy is one of the primary treatments for esophageal squamous cell carcinoma (ESCC). Identification of novel radio-sensitizing agents will improve the therapeutic outcome of radiotherapy. This study aimed to determine the radio-sensitizing effect of the antipsychotic agent thioridazine in ESCC and explored the underlying mechanisms. MATERIAL AND METHODS ECA-109 and TE-1 ESCC cells were treated with thioridazine and radiotherapy alone and in combination. Cell survival was measured by MTT assay. Cell cycle and apoptosis were monitored by flow cytometry. Western blot analysis was used to analyze the expression of phospho-PI3K, phosphor-AKT, phospho-mTOR, Caspase-3, Caspase-9, Bax, Bcl-2, Bal-xl, Bak, and p53. The xenograft mouse model was used to study the in vivo anticancer effect of thioridazine and irradiation. RESULTS Combined treatment with thioridazine and irradiation significantly reduced viability of ESCC cells compared with thioridazine or irradiation treatment alone. Thioridazine and irradiation treatment induced G0/G1 phases cell cycle arrest through down-regulation of CDK4 and cyclinD1. In addition, thioridazine and irradiation treatment induced apoptosis through up-regulation of cleaved capase-3 and 9, as well as an increase in the expression of Bax and Bak and a decrease in the expression of Bcl-2 and Bcl-xl. Furthermore, thioridazine and irradiation treatment inhibited the PI3K-AKT-mTOR pathway and up-regulated the expression of p53. In xenograft mice, thioridazine and irradiation reduced ESCC tumor growth. CONCLUSIONS Thioridazine sensitizes ESCC cells to radiotherapy. Thioridazine may play a role in ESCC radiation therapy as a promising radiosensitizer.

[miR-181b-5p promotes cell proliferation and induces apoptosis in human acute myeloid leukemia by targeting PAX9].

Objective To investigate the effects of miR-181b-5p on cells proliferation and apoptosis in acute myeloid leukemia (AML) by targeting paired box 9 (PAX9). Methods The relationship between expression level of PAX9 and prognosis in AML patients was analyzed by gene expression profiling interactive analysis (GEPIA) database and The Cancer Genome Atlas (TCGA) database. Kasumi-1 and AML5 cells were transfected with empty vector (Vector group) or PAX9 (PAX9 group). The proliferation activity was detected by CCK-8 assay, and cells cycle and apoptosis were detected by flow cytometry. Expressions of cyclin-dependent kinase 2 (CDK2), cyclin B1 (CCNB1), B-cell lymphoma 2 (Bcl2) and Bcl2-associated X protein (BAX) were detected by Western blot analysis. The targeted microRNA (miRNA) by PAX9 was predicted by bioinformatics analysis, and the targeted effect was verified by luciferase reporter assay. The level of PAX9 mRNA was detected by real-time quantitative PCR, and expression of PAX9 protein was detected by Western blot analysis. Kasumi-1 and AML5 cells were transfected with miR-NC (miR-NC group) or miR-181b-5p (miR-181b-5p group). The cells were further transfected with PAX9 (miR-181b-5p combined with PAX9 group) in miR-181b-5p group. The proliferation, cycle and apoptosis of cells were detected by the above methods.Results GEPIA and TCGA databases showed that the expression of PAX9 was down-regulated in AML patients, which was correlated with poor prognosis. In Kasumi-1 and AML5 cells, compared with Vector group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were decreased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were increased in PAX9 group. It was confirmed by double luciferase reporter assay that PAX9 was the target gene of miR-181b-5p. Compared with miR-NC group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were increased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were decreased in miR-181b-5p group. Compared with miR-181b-5p group, proliferation activity of cells, percentage of cells in S phase, and expressions of CDK2, CCNB1 and Bcl2 proteins were decreased, while percentage of cells in G0/G1 phase, apoptosis rate and the expression of BAX protein were increased in miR-181b-5p combined with PAX9 group. Conclusion The miR-181b-5p can promote the proliferation of AML cells and delay apoptosis by inhibiting PAX9.

Clinical Significance of EZH2 in Acute Myeloid Leukemia.

In this paper, we have focused on the investigation of the expression level of the enhancer of zeste homolog 2 (EZH2) gene in bone marrow mononuclear cells of acute myeloid leukemia (AML) patients and analyze the relationship between EZH2 gene expression and EMI. The expression of EZH2mRNA in bone marrow mononuclear cells of 26 patients with incipient AML was detected by qRT-PCR, and the relationship between EZH2mRNA expression and clinical characteristics was analyzed. EZH2 mRNA expression was increased in 26 AML patients. EZH2 gene expression in male patients was significantly higher than that in female patients. The expression of EZH2 in the group with extramedullary infiltration (EMI) was significantly higher than that in the group without EMI. The patients were divided into different groups according to the chromosomal karyotype and prognosis. Statistical analysis showed that the expression level of the medium-risk group was significantly higher than that of the low-risk group, while there was no statistical difference in other groups (P > 0.05). The expression of EZH2 gene in AML patients was closely related to EMI, and the expression of EZH2 in AML cells was closely related to cell migration ability. EZH2 is expected to be one of the indicators of disease recurrence.

HER2-targeted antibody-drug conjugate induces host immunity against cancer stem cells.

We previously tested HER2-targeted antibody-drug conjugates (ADCs) in immunocompromised (SCID) mice, precluding evaluation of host immunity, impact on cancer stem cells (CSCs), and potential benefit when combined with PD-L1 blockade. In this study, we tested HER2-targeted ADC in two immunocompetent mouse tumor models. HER2-targeted ADC specifically inhibited the growth of HER2-expressing tumors, prolonged animal survival, and reduced HER2+ and PD-L1+ cells. ADC + anti-PD-L1 antibody augmented therapeutic efficacy, modulated immune gene signatures, increased the number and function of CD3+ and CD19+ tumor-infiltrating lymphocytes (TILs), induced tumor antigen-specific immunological memory, stimulated B cell activation, differentiation, and IgG1 production both systemically and in the tumor microenvironment. In addition, ADC therapy modulated T cell subsets and their activation in TILs. Furthermore, HER2-targeted ADC reduced the number and tumorigenicity of ALDHhi CSCs. This study demonstrates that HER2-targeted ADC effectively targets ALDHhi CSCs and this effect is augmented by co-administration of anti-PD-L1 antibody.

Efficacy and safety of MIL60 compared with bevacizumab in advanced or recurrent non-squamous non-small cell lung cancer: a phase 3 randomized, double-blind study.

BACKGROUND: We compared the efficacy, safety, and immunogenicity of MIL60 with reference bevacizumab as first-line treatment in patients with advanced or recurrent non-squamous non-small cell lung cancer (NSCLC) in this phase 3, randomized, double-blind study. METHODS: Patients with untreated advanced or recurrent NSCLC were randomized (1:1 ratio) to receive either MIL60 or bevacizumab in combination with paclitaxel/carboplatin. Patients with non-progressive disease continued maintenance single-agent MIL60 until disease progression, or intolerable toxicity. The primary endpoint was the 12-week objective response rates (ORR12) by independent review committee (IRC) using RECIST 1.1. Bioequivalence was established if the ORR ratio located between 0.75 and 1/0.75. The trial was registered with clinicaltrials.gov (NCT03196986). FINDINGS: Between Aug 23, 2017, and May 8, 2019, 517 patients were randomly assigned to MIL60 group (n=257) and bevacizumab group (n=260). In the full analysis set (FAS) population including all randomized and evaluable patients who received at least one dose of MIL60 or bevacizumab, the ORR12 in MIL60 group and bevacizumab group were 48.6% and 43.1%, respectively. The ORR ratio of these two groups were 1.14 (90% CI 0.97-1.33), which fell within the pre-specified equivalence boundaries (0.75-1/0.75). The median DOR was 5.7 months (95% CI 4.5-6.2) for MIL60 and 5.6 months (95% CI 4.3-6.4) for bevacizumab. No significant difference was noted in median PFS (7.2 vs. 8.1 months; HR 1.01, 95% CI 0.78-1.30, p=0.9606) and OS (19.3 vs. 16.3 months; HR 0.81, 95% CI 0.64-1.02, p=0.0755). Safety and tolerability profiles were similar between the two groups. No patient detected positive for Anti-drug antibody (ADA). INTERPRETATION: The efficacy, safety and immunogenicity of MIL60 were similar with bevacizumab, providing an alternative treatment option for advanced or recurrent non-squamous NSCLC. FUNDING: This study was sponsored by Betta Pharmaceutical Co., Ltd.

The clinical study on treatment of CD19-directed chimeric antigen receptor-modified T cells in a case of refractory Richter syndrome.

Richter syndrome (RS) indicates the transformation of chronic lymphocytic leukemia (CLL) into an aggressive lymphoma (mostly DLBCL). Richter syndrome is a rare complication with an aggressive clinical course, bearing an unfavorable prognosis. Currently, there is no effective treatment for it. As a novel cellular-based immune therapy, chimeric antigen receptor-modified T (CART) cells treatment is gradually used in treating hematological malignancies, especially in CD19+ B-cell malignancy. Therefore, CD19-directed chimeric antigen receptor-modified T cells (CART-19) treatment is promising to be used as a new method for RS patients. In our study, one RS patient expressing high level of CD19 molecule was enrolled in clinical trial; he has received a series of treatments but did not achieve a satisfactory therapeutic effect. The patient totally received 3.55 × 108 autologous CART-19 cells infusion. After CART-19 infusion, the mainly clinical side effect was repeated fever. The maximal duration period was 24 days and the highest temperature was 40.1°C. Pancytopenia and significantly serum cytokines level rise were observed, including IFN-γ, IL-6, and IL-10. Before discharge, the level of cytokines reduced to normal levels. In addition, we detected the serum biochemical indices as like K+ , Ca2+ , creatinine, and glutamic-pyruvic transaminase, all of these indices were normal. This showed that there was no tumor necrosis syndrome after treatment. The proportion of B cells in patient's peripheral blood decreased from 72% to 40.2% after infusion, co-occurring with reduction in lymph nodes and hematopoietic reconstitution. Based on the recent revolution in the therapeutic landscape for hematological malignancies including B-cell lymphomas, CART-CD19 cell therapy as a new therapeutic option for RS might be available in the coming years. It aims to reduce patient's tumor burden, prolong their survival time, and provide opportunities for other sequential therapy such as chemotherapy and bone marrow transplantation.

HLA-Mismatched Microtransplant in Older Patients Newly Diagnosed With Acute Myeloid Leukemia: Results From the Microtransplantation Interest Group.

IMPORTANCE: The outcome of older patients with acute myeloid leukemia (AML) remains unsatisfactory. Recent studies have shown that HLA-mismatched microtransplant could improve outcomes in such patients. OBJECTIVE: To evaluate outcomes in different age groups among older patients with newly diagnosed AML who receive HLA-mismatched microtransplant. DESIGN, SETTING, AND PARTICIPANTS: This multicenter clinical study included 185 patients with de novo AML at 12 centers in China, the United States, and Spain in the Microtransplantation Interest Group. Patients were divided into the following 4 age groups: 60 to 64 years, 65 to 69 years, 70 to 74 years, and 75 to 85 years. The study period was May 1, 2006, to July 31, 2015. EXPOSURES: Induction chemotherapy and postremission therapy with cytarabine hydrochloride with or without anthracycline, followed by highly HLA-mismatched related or fully mismatched unrelated donor cell infusion. No graft-vs-host disease prophylaxis was used. MAIN OUTCOMES AND MEASURES: The primary end point of the study was to evaluate the complete remission rates, leukemia-free survival, and overall survival in different age groups. Additional end points of the study included hematopoietic recovery, graft-vs-host disease, relapse rate, nonrelapse mortality, and other treatment-related toxicities. RESULTS: Among 185 patients, the median age was 67 years (range, 60-85 years), and 75 (40.5%) were female. The denominators in adjusted percentages in overall survival, leukemia-free survival, relapse, and nonrelapse mortality are not the sample proportions of observations. The overall complete remission rate was not significantly different among the 4 age groups (75.4% [52 of 69], 70.2% [33 of 47], 79.1% [34 of 43], and 73.1% [19 of 26). The 1-year overall survival rates were 87.7%, 85.8%, and 77.8% in the first 3 age groups, which were much higher than the rate in the fourth age group (51.7%) (P = .004, P = .008, and P = .04, respectively). The 2-year overall survival rates were 63.7% and 66.8% in the first 2 age groups, which were higher than the rates in the last 2 age groups (34.2% and 14.8%) (P = .02, P = .03, P < .001, and P < .001, respectively). The 1-year cumulative incidences of nonrelapse mortality were 10.2%, 0%, 3.4%, and 26.0% in the 4 age groups and 8.1% in all patients. The median times to neutrophil and platelet recovery were 12 days and 14 days after induction chemotherapy, respectively. Five patients had full or mixed donor engraftment, and 30.8% (8 of 26) of patients demonstrated donor microchimerism. Two patients (1.1%) developed severe acute graft-vs-host disease. CONCLUSIONS AND RELEVANCE: Microtransplant achieved a high complete remission rate in AML patients aged 60 to 85 years and higher 1-year overall survival in those aged 60 to 74 years.

[Thioridazine Sensitizes Apoptotic Effect of TRAIL in Human Lung Cancer PC9 Cells Through ER Stress Mediated Up-regulation of DR5].

BACKGROUND: Tumor necrosis factor-related apoptosis-inducting ligand (TRAIL) can induce apoptosis of tumor cells, however, various of tumor cells may survive because of resistance to TRAIL-mediated apoptosis. This study is to observe the proliferation inhibition effect of TRAIL sensitized by thioridazine on PC9 cells through endoplasmic reticulum (ER) stress mediated up-regulation of death receptor 5 (DR5) and investigate its mechanism. METHODS: PC9 cells were treated with different concentrations of thioridazine and TRAIL alone or in combination. Cell proliferation was measured by MTT assay, and cell apoptosis and cell-surface DR5 were detected by flow cytometry. Western blotting was utilized to measure the expressions of ER stress-related proteins glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP), p-PKR-like ER kinase (PERK), p-eukaryotic initiation factor-2α (eIF2α), activating transcription factor 4 (ATF4) and apoptosis-related proteins caspase-3, caspase-9, caspase-8, PARP, DR5. RESULTS: Thioridazine inhibited the proliferation of PC9 cells in a dose-dependent manner (P<0.05). Thioridazine increased the inhibition and apoptosis of PC9 cells and up-regulated the expression of cell-surface DR5 induced by TRAIL. Flow cytometry showed that compared with TRAIL group, combination group of TRAIL and thioridazine increased cell apoptotic rates significantly (P<0.05). Western blotting indicated that compared with TRAIL group, expressions of Cleaved-caspase-8, Cleaved-PARP and DR5 increased significantly in combination group of TRAIL and thioridazine. The induction of DR5 and pro-apoptotic effect were mediated through activation of ER stress accompanying by increased synthesis of GRP78 and CHOP, which can be blocked by adding of ER stress inhibitor 4-PBA. CONCLUSIONS: Thioridazine enhanced proliferation inhibition effect of TRAIL in PC9 cells may be facilitated through ER stress mediated upregulation of DR5.
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Humanized CD7 nanobody-based immunotoxins exhibit promising anti-T-cell acute lymphoblastic leukemia potential.

BACKGROUND: Nanobodies, named as VHHs (variable domain of heavy chain of HCAb [heavy-chain antibodies]), are derived from heavy-chain-only antibodies that circulate in sera of camelids. Their exceptional physicochemical properties, possibility of humanization, and unique antigen recognition properties make them excellent candidates for targeted delivery of biologically active components, including immunotoxins. In our previous efforts, we have successfully generated the monovalent and bivalent CD7 nanobody-based immunotoxins, which can effectively trigger the apoptosis of CD7-positive malignant cells. To pursue the possibility of translating those immunotoxins into clinics, we humanized the nanobody sequences (designated as dhuVHH6) as well as further truncated the Pseudomonas exotoxin A (PE)-derived PE38 toxin to produce a more protease-resistant form, which is named as PE-LR, by deleting majority of PE domain II. METHODS AND RESULTS: Three new types of immunotoxins, dhuVHH6-PE38, dVHH6-PE-LR, and dhuVHH6-PE-LR, were successfully constructed. These recombinant immunotoxins were expressed in Escherichia coli and showed that nanobody immunotoxins have the benefits of easy soluble expression in a prokaryotic expression system. Flow cytometry results revealed that all immunotoxins still maintained the ability to bind specifically to CD7-positive T lymphocyte strains without binding to CD7-negative control cells. Laser scanning confocal microscopy revealed that these proteins can be endocytosed into the cytoplasm after binding with CD7-positive cells and that this phenomenon was not observed in CD7-negative cells. WST-8 experiments showed that all immunotoxins retained the highly effective and specific growth inhibition activity in CD7-positive cell lines and primary T-cell acute lymphoblastic leukemia (T-ALL) cells. Further in vivo animal model experiments showed that humanized dhuVHH6-PE38 immunotoxin can tolerate higher doses and extend the survival of NOD-Prkdcem26Il2rgem26Nju (NCG) mice transplanted with CEM cells without any obvious decrease in body weight. Further studies on NCG mice model with patient-derived T-ALL cells, dhuVHH6-PE38 treatment, significantly prolonged mice survival with ~40% survival improvement. However, it was also noticed that although dhuVHH6-PE-LR showed strong antitumor effect in vitro, its in vivo antitumor efficacy was disappointing. CONCLUSION: We have successfully constructed a targeted CD7 molecule-modified nanobody (CD7 molecule-improved nanobody) immunotoxin dhuVHH6-PE38 and demonstrated its potential for treating CD7-positive malignant tumors, especially T-cell acute lymphoblastic leukemia.

Gene-modified NK-92MI cells expressing a chimeric CD16-BB-ζ or CD64-BB-ζ receptor exhibit enhanced cancer-killing ability in combination with therapeutic antibody.

Natural killer (NK) cells play a pivotal role in monoclonal antibody-mediated immunotherapy through the antibody-dependent cell-mediated cytotoxicity (ADCC) mechanism. NK-92MI is an interleukin-2 (IL-2)-independent cell line, which was derived from NK-92 cells with superior cytotoxicity toward a wide range of tumor cells in vitro and in vivo. Nonetheless, the Fc-receptor (CD16) that usually mediates ADCC is absent in NK-92 and NK-92MI cells. To apply NK-92MI cell-based immunotherapy to cancer treatment, we designed and generated two chimeric receptors in NK-92MI cells that can bind the Fc portion of human immunoglobulins. The construct includes the low-affinity Fc receptor CD16 (158F) or the high-affinity Fc receptor CD64, with the addition of the CD8a extracellular domain, CD28 transmembrane domains, two costimulatory domains (CD28 and 4-1BB), and the signaling domain from CD3ζ. The resulting chimeric receptors, termed CD16-BB-ζ and CD64-BB-ζ, were used to generate modified NK-92MI cells expressing the chimeric receptor, which were named NK-92MIhCD16 and NK-92MIhCD64 cells, respectively. We found that NK-92MIhCD16 and NK-92MIhCD64 cells significantly improved cytotoxicity against CD20-positive non-Hodgkin's lymphoma cells in the presence of rituximab. These results suggest that the chimeric receptor-expressing NK-92MI cells may enhance the clinical responses to currently available anticancer monoclonal antibodies.

IL-2 augments the therapeutic efficacy of adoptively transferred B cells which directly kill tumor cells via the CXCR4/CXCL12 and perforin pathways.

We previously reported that antitumor B cells directly kill tumor cells via the Fas/FasL pathway and are regulated by IL-10. In this study, we defined additional mechanisms involved in B cell antitumor immunity. Administration of IL-2 significantly augmented the therapeutic efficacy of adoptively transferred tumor-draining lymph node (TDLN) B cells which express IL- 2R. Culture supernatant of purified B splenocytes harvested from the mice that received adoptive transfer of 4T1 TDLN B cells plus IL-2 administration produced larger amounts of IgG which bound to 4T1, resulting in 4T1 lysis. Furthermore, we detected CXCR4 expression on 4T1 TDLN B cells, and 4T1 tumor cells produced its ligand CXCL12. Transwell experiments demonstrated the chemoattraction of CXCR4-expressing 4T1 TDLN B cells towards CXCL12- producing 4T1 cells. Blockade of CXCR4 using a CXCR4-specific inhibitor, AMD3100, significantly reduced the killing of 4T1 tumor cells by 4T1 TDLN B cells. Blockade of FasL and CXCR4 concurrently inhibited B cell-mediated direct killing of tumor cells in an additive manner, indicating that both Fas/FasL and CXCL12/CXCR4 pathways are involved in the direct killing of 4T1 cells by 4T1 TDLN B cells. TDLN B cells produced perforin. Additional transwell experiments showed that effector B cells could directly kill tumor cells in cell-cell contact via the Fas/FasL and CXCR4/CXCL12 pathways as well as perforin, while without cell contact, perforin secreted by B cells led to tumor cell cytotoxicity. These findings underscore the diversity of function by which B cells can play an important role in the host immune response to tumor.

Therapeutic Efficacy of Cancer Stem Cell Vaccines in the Adjuvant Setting.

Dendritic cell (DC)-based vaccine strategies aimed at targeting cancer stem-like cells (CSC) may be most efficacious if deployed in the adjuvant setting. In this study, we offer preclinical evidence that this is the case for a CSC-DC vaccine as tested in murine models of SCC7 squamous cell cancer and D5 melanoma. Vaccination of mice with an ALDH(high) SCC7 CSC-DC vaccine after surgical excision of established SCC7 tumors reduced local tumor relapse and prolonged host survival. This effect was augmented significantly by simultaneous administration of anti-PD-L1, an immune checkpoint inhibitor. In the minimal disease setting of D5 melanoma, treatment of mice with ALDH(high) CSC-DC vaccination inhibited primary tumor growth, reduced spontaneous lung metastases, and increased host survival. In this setting, CCR10 and its ligands were downregulated on ALDH(high) D5 CSCs and in lung tissues, respectively, after vaccination with ALDH(high) D5 CSC-DC. RNAi-mediated attenuation of CCR10 blocked tumor cell migration in vitro and metastasis in vivo T cells harvested from mice vaccinated with ALDH(high) D5 CSC-DC selectively killed ALDH(high) D5 CSCs, with additional evidence of humoral immunologic engagement and a reduction in ALDH(high) cells in residual tumors. Overall, our results offered a preclinical proof of concept for the use of ALDH(high) CSC-DC vaccines in the adjuvant setting to more effectively limit local tumor recurrence and spontaneous pulmonary metastasis, as compared with traditional DC vaccines, with increased host survival further accentuated by simultaneous PD-L1 blockade. Cancer Res; 76(16); 4661-72. ©2016 AACR.

[Mechanism of Killing Effect of Thioridazine on Human Lung Cancer PC9 Cells].

BACKGROUND: Recent research shows thioridazine which is a kind of phenothiazine antipsychotic drugs can inhibit the proliferation of various tumor cells in vitro, but the role of thioridazine on lung cancer has not been reported. So we choose PC9 cell lines as the research object, the aim is to oberve the killing effect of thioridazine on PC9 cells and investigate its possible mechanism. METHODS: After being treated with different concentrations of thioridazine, the proliferation of PC9 cells was determined by methyl thiazolyltetrazolium (MTT) assay. Flow cytometry was used to measure the cell cycle distribution and apoptosis. The expressions of cell cycle-associated protein CyclinD1 and apoptosis-related proteins Caspase-3, Caspase-8, Caspase-9, Bcl-2, Bax and Bcl-xl were detected by Western blot. RESULTS: The proliferation of PC9 cells was significantly inhibited by thioridazine in a dose- and time-dependent manner. Flow cytometry showed that cell cycle was arrested in G0/G1 phase and the apoptotic rates were significantly increased with the increasing concentration of thioridazine. Compared with the control group, the differences were statistically significant (P<0.05). Western blot analysis showed that, compared with the control group, thioridazine reduced the expressions of CyclinD1, Bcl-2 and Bcl-xl (P<0.01) and increased the expression of Bax (P<0.01). In the mean time, thioridazine promoted the activities of Caspase-3, Caspase-8 and Caspase-9 (P<0.01). CONCLUSIONS: The mechanism of thioridazine inhibiting the proliferation of PC9 cells may be related to stimulation of Caspase apoptotic pathway, down-regulation of CyclinD1, Bcl-2, Bcl-xl and up-regulation of Bax.

[Heterogeneity of mesenchymal stem cells in culture in vitro].

Mesenchymal stem cells (MSC) are the ideal adult stem cells in cell/gene therapy and tissue engineering for their features of easily-handling, highly proliferative capacity in vitro, low immunogenicity and immunomodulatory ability. MSC, as a kind of cellular drug, have been utilized in a phase III clinical trial to treat refractory graft-versus-host disease (GVHD). However, the essences of MSC in culture remain elusive so far. Whether the cells expanded in vitro are stem cells per se, and if not, why expanded MSC maintain their multiple differentiation ability? And are the MSC cultivated in vitro homogeneous and if not, what the heterogeneity stands for? Focusing on the heterogeneity of MSC in culture in vitro, the above questions are briefly discussed in this review.