Yongwei Yu

Macrophage-derived chemokine gene transfer results in tumor regression in murine lung carcinoma model through efficient induction of antitumor immunity

Chemokine gene transfer represents a promising approach in the treatment of malignancies. Macrophage-derived chemokine (MDC) (CCL22) belongs to the CC chemokine family and is a strong chemoattractant for dendritic cells (DC), NK cells and T cells. Using adenoviral vectors, human MDC gene was transferred in vivo to investigate its efficacy to induce an antitumor response and to determine the immunologic mechanisms involved. We observed that intratumoral injection of recombinant adenovirus encoding human MDC (AdMDC) resulted in marked tumor regression in a murine model with pre-established subcutaneous 3LL lung carcinoma and induced significant CTL activity. The antitumor response was demonstrated to be CD4+ T cell- and CD8+ T cell-dependent. Administration of AdMDC induced chemoattraction of DC to the tumor site, facilitated DC migration to draining lymph nodes or spleen, and finally activated DC to produce high levels of IL-12. Furthermore, a significant increase of IL-4 production within the tumors was observed early after the AdMDC administration and was followed by the increase of IL-12 and IL-2 production. The levels of IL-2, IL-12 and IFN-γ in serum, lymph nodes and spleen were also found to be higher in mice treated with AdMDC as compared with that in AdLacZ- or PBS-treated mice. The antitumor response induced by AdMDC was markedly impaired in IL-4 knockout mice, suggesting an important role of IL-4 in the induction of antitumor immunity by MDC. These results suggest that MDC gene transfer might elicit significant antitumor effects through efficient induction of antitumor immunity and might be of therapeutic potentials for cancer.

Oncogenic CUL4A determines the response to thalidomide treatment in prostate cancer

Thalidomide is experimentally used to treat various human cancers; however, clinical responses to thalidomide are sporadic. Here we demonstrate that CUL4A plays an oncogenic role in prostate cancer development and prostate cancer cells with higher level of CUL4A are particularly sensitive to thalidomide treatment. We show that CUL4A is frequently overexpressed in human primary prostate cancer and cell lines. Notably, subjects with tumors that highly expressed CUL4A had poor overall survival. CUL4A downregulation inhibited cell proliferation and induced apoptosis in vitro and in vivo, whereas CUL4A overexpression transformed human normal prostate epithelial cells and promoted invasion, which was attenuated by the extracellular signal-regulated kinase (ERK) inhibitor. We further show that the sensitivity to thalidomide is positively correlated with CUL4A expression in a panel of prostate cell lines. Ectopic CUL4A expression greatly enhanced sensitivity to thalidomide, while its downregulation conferred resistance to this drug. Mechanistically, thalidomide decreased CUL4A in a time- and dose-dependent manner, consequently leading to inaction of ERK pathway. Finally, we show that cereblon level is correlated with CUL4A expression and downregulated in thalidomide-resistant prostate cancer cell. Our results offer the first evidence that CUL4A is a potential therapeutic target for prostate cancer and may serve as a biomarker for assessing prognosis of human prostate cancer and response to thalidomide treatment.

miR-663 Induces Castration-Resistant Prostate Cancer Transformation and Predicts Clinical Recurrence

Castration‐resistant prostate cancer (CRPC) and its treatment are challenging issues in prostate cancer management. Here, we report that miR‐663 is upregulated in CRPC tissues. Overexpression of miR‐663 in prostate LNCaP cells promotes cell proliferation and invasion, neuroendocrine differentiation, and reduction in dihydrotestosterone‐induced upregulation of prostate‐specific antigen expression. Furthermore, results of in situ hybridization show that miR‐663 expression is correlated with Gleason score and TNM stage and is an independent prognostic predictor of clinical recurrence. Together, these findings suggest that miR‐663 is a potential oncomiR for CRPC and may serve as a tumor biomarker for the early diagnosis of CRPC. J. Cell. Physiol. 229: 834–844, 2014.

Histone methyltransferase SETDB1 is required for prostate cancer cell proliferation, migration and invasion

SETDB1 has been established as an oncogene in a number of human carcinomas. The present study was to evaluate the expression of SETDB1 in prostate cancer (PCa) tissues and cells and to preliminarily investigate the role of SETDB1 in prostate tumorigenesis in vitro. Quantitative reverse transcription polymerase chain reaction (qRT-PCR) and immunohistochemistry (IHC) were used to detect the expression of SETDB1 in PCa tissues, adjacent normal tissues, benign prostatic hyperplasia (BPH) tissues, PCa cell lines and normal prostate epithelial cells. The results suggested that SETDB1 was upregulated in human PCa tissues compared with normal tissues at the mRNA and protein levels. The role of SETDB1 in proliferation was analyzed with cell counting kit-8, colony-forming efficiency and flow cytometry assays. The results indicated that downregulation of SETDB1 by siRNA inhibited PCa cell growth, and induced G0/G1 cell cycle arrest. The PCa cell migration and invasion decreased by silcencing SETDB1 which were assessed by using in vitro scratch and transwell invasion assay respectively. Our data suggested that SETDB1 is overexpressed in human PCa. Silencing SETDB1 inhibited PCa cell proliferation, migration and invasion.

Periostin expression in intra-tumoral stromal cells is prognostic and predictive for colorectal carcinoma via creating a cancer-supportive niche

Periostin (POSTN) expression in cancer cells and circulation has been related to poor prognosis of colorectal carcinoma (CRC). However, the role of POSTN expressed in intra-tumoral stroma on CRC progression remains largely unknown. This study enrolled 1098 CRC patients who received surgical treatment in Shanghai and Guangzhou, Mainland China. In Shanghai cohort, immunohistochemistry score of stromal POSTN expression increased consecutively from adjacent mucosa, primary CRC tissues, to metastatic CRC tissues (P < 0.001), while medium- and high-stromal POSTN expression, rather than epithelial POSTN expression, independently predicted unfavorable prognoses of CRC, adjusted for covariates including TNM stage and postoperative chemotherapy in multivariate Cox models. The results in Shanghai cohort were faithfully replicated in Guangzhou cohort. Stromal POSTN expression dose-dependently predicted an unfavorable prognosis of stage III CRC patients with postoperative chemotherapy in both cohorts. POSTN derived from colonic fibroblasts or recombinant POSTN significantly promoted proliferation, anchorage independent growth, invasion, and chemo-resistance of CRC cells; whereas these effects were counteracted via targeting to PI3K/Akt or Wnt/β-catenin signaling pathway. CRC cell RKO-derived factor(s) significantly induced POSTN production in colonic fibroblasts and autocrine POSTN promoted proliferation, migration, and anchorage independent growth of fibroblasts. Conclusively, stromal POSTN is prognostic and predictive for CRC via creating a niche to facilitate cancer progression. Targeting POSTN-induced signaling pathways may be therapeutic options for metastatic or chemoresistant CRC.

Nonsense and missense mutation of mitochondrial ND6 gene promotes cell migration and invasion in human lung adenocarcinoma.

BackgroundPrevious study showed that mitochondrial ND6 (mitND6) gene missense mutation resulted in NADH dehydrogenase deficiency and was associated with tumor metastasis in several mouse tumor cell lines. In the present study, we investigated the possible role of mitND6 gene nonsense and missense mutations in the metastasis of human lung adenocarcinoma.MethodsThe presence of mitND6 gene mutations was screened by DNA sequencing of tumor tissues from 87 primary lung adenocarcinoma patients and the correlation of the mutations with the clinical features was analyzed. In addition, we constructed cytoplasmic hybrid cells with denucleared primary lung adenocarcinoma cell as the mitochondria donor and mitochondria depleted lung adenocarcinoma A549 cell as the nuclear donor. Using these cells, we studied the effects of mitND6 gene nonsense and missense mutations on cell migration and invasion through wounding healing and matrigel-coated transwell assay. The effects of mitND6 gene mutations on NADH dehydrogenase activity and ROS production were analyzed by spectrophotometry and flow cytometry.ResultsmitND6 gene nonsense and missense mutations were detected in 11 of 87 lung adenocarcinoma specimens and was correlated with the clinical features including age, pathological grade, tumor stage, lymph node metastasis and survival rate. Moreover, A549 cell containing mitND6 gene nonsense and missense mutation exhibited significantly lower activity of NADH dehydrogenase, higher level of ROS, higher capacity of cell migration and invasion, and higher pAKT and pERK1/ERK2 expression level than cells with the wild type mitND6 gene. In addition, NADH dehydrogenase inhibitor rotenone was found to significantly promote the migration and invasion of A549 cells.ConclusionsOur data suggest that mitND6 gene nonsense and missense mutation might promote cell migration and invasion in lung adenocarcinoma, probably by NADH dehydrogenase deficiency induced over-production of ROS.

Tumor cells positive and negative for the common cancer stem cell markers are capable of initiating tumor growth and generating both progenies.

The cancer stem cell (CSC) model depicts that tumors are hierarchically organized and maintained by CSCs lying at the apex. CSCs have been “identified” in a variety of tumors through the tumor-forming assay, in which tumor cells distinguished by a certain cell surface marker (known as a CSC marker) were separately transplanted into immunodeficient mice. In such assays, tumor cells positive but not negative for the CSC marker (hereby defined as CSC+ and CSC− cells, respectively) have the ability of tumor-forming and generating both progenies. However, here we show that CSC+ and CSC− cells exhibit similar proliferation in the native states. Using a cell tracing method, we demonstrate that CSC− cells exhibit similar tumorigenesis and proliferation as CSC+ cells when they were co-transplanted into immunodeficient mice. Through serial single-cell derived subline construction, we further demonstrated that CSC+ and CSC− cells from CSC marker expressing tumors could invariably generate both progenies, and their characteristics are maintained among different generations irrespective of the origins (CSC+-derived or CSC−-derived). These findings demonstrate that tumorigenic cells cannot be distinguished by common CSC markers alone and we propose that cautions should be taken when using these markers independently to identify cancer stem cells due to the phenotypic plasticity of tumor cells.

Neural protein gamma-synuclein interacting with androgen receptor promotes human prostate cancer progression

BackgroundGamma-synuclein (SNCG) has previously been demonstrated to be significantly correlated with metastatic malignancies; however, in-depth investigation of SNCG in prostate cancer is still lacking. In the present study, we evaluated the role of SNCG in prostate cancer progression and explored the underlying mechanisms.MethodsFirst, alteration of SNCG expression in LNCaP cell line to test the ability of SNCG on cellular properties in vitro and vivo whenever exposing with androgen or not. Subsequently, the Dual-luciferase reporter assays were performed to evaluate whether the role of SNCG in LNCaP is through AR signaling. Last, the association between SNCG and prostate cancer progression was assessed immunohistochemically using a series of human prostate tissues.ResultsSilencing SNCG by siRNA in LNCaP cells contributes to the inhibition of cellular proliferation, the induction of cell-cycle arrest at the G1 phase, the suppression of cellular migration and invasion in vitro, as well as the decrease of tumor growth in vivo with the notable exception of castrated mice. Subsequently, mechanistic studies indicated that SNCG is a novel androgen receptor (AR) coactivator. It interacts with AR and promotes prostate cancer cellular growth and proliferation by activating AR transcription in an androgen-dependent manner. Finally, immunohistochemical analysis revealed that SNCG was almost undetectable in benign or androgen-independent tissues prostate lesions. The high expression of SNCG is correlated with peripheral and lymph node invasion.ConclusionsOur data suggest that SNCG may serve as a biomarker for predicting human prostate cancer progression and metastasis. It also may become as a novel target for biomedical therapy in advanced prostate cancer.

A genetic polymorphism affects the risk and prognosis of renal cell carcinoma: Association with follistatin-like protein 1 expression

Few single nucleotide polymorphisms (SNPs) associated with the risk of renal cell carcinoma (RCC) have been identified, yet genetic predisposition contributes significantly to this malignancy. We previously showed that follistatin-like 1 (FSTL1) was significantly down-regulated in clear cell RCC (ccRCC), in particular metastatic ccRCC. In the present study, we systemically investigated the associations of the 6 SNPs within FSTL1-coding genomic region with RCC risk and postoperative prognosis. Age- and gender-matched case-control study (417 vs 855) indicated that rs1259293 variant genotype CC was significantly associated with an increased risk of RCC, with an odds ratio of 2.004 (95% confidence internal [CI] = 1.190–3.375). Multivariate Cox regression analysis in 309 of 417 cases showed that rs1259293 genotype (CC vs TT + CT) independently predicted an unfavorable prognosis, with a hazard ratio of 2.531 (95% CI = 1.052–6.086). Expression of FSTL1 was significantly higher in adjacent renal tissues than in tumors, and significantly higher in the tissues with rs1259293 TT genotype than in those with rs1259293 TC+CC genotypes. rs1259293 C allele might generate a CTCF binding site that blocks trans-activation of FSTL1 expression. Our results indicate that rs1259293 is associated with an increased risk and unfavorable postoperative prognosis of RCC, possibly by down-regulating FSTL1 expression in renal tissues.

Granulocyte–macrophage colony-stimulating factor induces the differentiation of murine erythroleukaemia cells into dendritic cells

Dendritic cells (DC) are professional antigen‐presenting cells (APC) within the immune system and antigen‐pulsed DC can be used as an effective vaccine for active immunotherapy of cancer. Granulocyte–macrophage colony‐stimulating factor (GM‐CSF) plays an important role in the generation of DC. We previously showed that GM‐CSF can induce murine erythroleukaemia cells (FBL‐3) to differentiate into monocyte‐like cells. To develop a new vaccinating method to stimulate the host immune response to leukaemia, we further investigate whether FBL‐3 cells induced by GM‐CSF can differentiate into DC in the present study. After being treated with GM‐CSF, FBL‐3 cells expressed high levels of 33D1 and NLDC‐145, which are the specific markers of DC. The expression of MHC‐II, B7‐1, B7‐2 and vascular cell adhesion molecule‐1 (VCAM‐1) was up‐regulated markedly; the typical morphology of DC were also observed by electron microscopy. Functionally, the GM‐CSF‐induced FBL‐3 cells could apparently stimulate the proliferation of naive allogeneic and autologous T lymphocytes and induce the generation of specific CTL more efficiently than the wild‐type FBL‐3 cells. Mice immunized with GM‐CSF‐induced FBL‐3 cells could resist the subsequent challenge with the wild‐type FBL‐3 cells. Collectively, these data indicate that GM‐CSF differentiates murine erythroleukaemia cells into DC phenotypically, morphologically and functionally. FBL‐3‐derived DC can be used as a new type of vaccine. Our results may have important implications for the immunotherapy of leukaemia.