Abstract. Cdc42, a Rho GTPase family member, is involved in cell transformation, proliferation, survival, invasion and metastasis of human cancer cells. Overexpression of Cdc42 has been reported in several types of human cancer. However, the underlying mechanisms are not well understood. The present study showed that Cdc42 was overexpressed in 80 of 110 primary lung cancer patients, and overexpression of Cdc42 was significantly associated with high TNM stage and lymph node metastasis. Moreover, RNAi-mediated suppression of Cdc42 expression reduced actin filopodia formation, migration and invasion potential of a highly metastatic lung cancer cell line, 801D. In parallel, 801D cells were treated with curcumin and the effect on the expression of the Cdc42 gene at the transcriptional and translational levels was analyzed by RT-PCR and Western blotting. Curcumin inhibited cell migration, invasion and downregulated Cdc42 gene and Cdc42-related target gene expression in 801D cells. It also induced rearrangements of the actin cytoskeleton. These effects mimicked those of Cdc42 knockdown. Furthermore, xenograft experiments confirmed the suppression of tumor growth and invasion in vivo, which was due to the effect of curcumin and the inhibition of Cdc42 by curcumin. Our results showing the downregulation of Cdc42 expression by curcumin in lung cancer cells taken together with the clinical data suggest a potential therapeutic role for curcumin in inducing Cdc42-mediated inhibition of invasion of lung cancer cells.

Abstract. The present study aimed to determine the levels of cathepsin B (cath B), cathepsin L (cath L), cystatin C, urokinase plasminogen activator (u-PA) and urokinase plasminogen activator receptor (u-PAR) in the sera of patients with lung cancer compared to healthy controls using ELISA. Concomitantly, the relationship between the components and clinicopathological prognosis was analyzed. The study included 30 healthy volunteers and 105 lung cancer patients. Blood samples were collected and cath B, cath L, cystatin C, u-PA and u-PAR measurements were made using ELISA. Results showed that the levels of cath B, cath L, cystatin C, u-PA and u-PAR were significantly higher in the patient group compared to the healthy controls. The significance was marked for cath B and mild for u-PAR in correlation with lymph node metastasis. There was no significance for other parameters. Notably, patients with a combination of high cystatin C and high cath B levels had significantly lower survival probability as compared to those with cystatin C + /cath B -or with cystatin C -/cath B -. Similarly, patients with a combination of high u-PA and u-PAR experienced significantly shorter survival. Furthermore, the univariate analysis revealed that cath B, u-PAR, lymph node metastases, stage and grade were related to survival. However, findings of the multivariate Cox analysis indicated that the sera levels of cath B, u-PAR and lymph node metastases may serve as independent prognostic variables in patients with lung cancer. IntroductionCathepsins are members of the lysosomal cysteine proteases family and are usually located inside a lysosome. Numerous studies showed a correlation of increased proteolytic activity of cysteine cathepsins with neoplastic transformation, tumor invasion and metastasis through the destruction of extracellular matrix components and basement membranes in tumor spread. Cathepsin B (cath B) is able to activate pro-urokinasetype plasminogen activator and enhance subsequent plasmin generation. Increased levels of cath B and L were observed in tissues of primary and metastatic tumors in a number of cancer types (1-3). The serum level of cath B may serve as a prognostic factor for patients with advanced melanoma. By contrast, the serum level of cath L was not statistically different in the control, non-metastatic and metastatic patient groups (3). Moreover, using immunohistochemical analysis, the overexpression of cath B and L was shown to correlate with more aggressive tumor behavior, early relapse and shorter survival (2). However, in lung cancer tissue, cath L did not reveal any association with prognosis (4).Cystatin C, an accurate marker of glomerular filtration rate and endogenous cysteine protease inhibitor, has been found in a variety of human tissues, but is mainly found in extracellular body fluid and serum. Increased levels of cystatin C in tumor tissues were shown to correlate with a favourable prognosis of cancer patients (5), whereas higher levels of cystatin C in body fluids have been associated with ...

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Tumour‐associated macrophage (TAM) is an important component in tumour microenvironment. Generally, TAM exhibits the function of M2‐like macrophage, which was closely related to angiogenesis and tumour progression. Dioscin, a natural steroidal saponin, has shown its powerful anti‐tumour activity recently. However, the mechanism of dioscin involved in immune regulation is still obscure. Here, we observed dioscin induced macrophage M2‐to‐M1 phenotype transition in vitro and inhibited IL‐10 secretion. Meanwhile, the phagocytosis of macrophages was enhanced. In subcutaneous lung tumour models, dioscin inhibited the augmentation of M2 macrophage populations. Furthermore, dioscin down‐regulated STAT3 and JNK signalling pathways in macrophages in vitro. In BMDMs, activating JNK and inhibiting STAT3 induce macrophages to M1 polarization while inhibiting JNK and activating STAT3 to M2 polarization. Additionally, condition mediums from dioscin‐pre‐treated macrophages inhibited the migration of 3LL cells and the tube‐formation capacity of HUVECs. What's more, dioscin‐mediated macrophage polarization inhibited the in vivo metastasis of 3LL cells. In conclusion, dioscin may act as a new anti‐tumour agent by inhibiting TAMs via JNK and STAT3 pathways in lung cancer.

Administration of donor-derived immature dendritic cells (DC) can prolong the survival of MHC-mismatched cardiac allografts. Genetic modification of DC by immunosuppressive molecules can enhance their potential tolerogenicity. In this study bone marrow derived immature DC were genetically modified by transforming growth factor (TGF) beta1 by recombinant Ad. TGF-beta(1) gene modified immature DC (TGF-beta-DC) displayed a characteristic phenotype of immature DC, decreased ability to secrete interleukin 12, and reduced allostimulatory ability. TGF-beta-DC induced alloantigen-specific T cell hyporesponsiveness in vitro and in vivo, and Th2 cytokine polarization. mRNA expression of donor MHC class II (Ia(b)) and human TGF-beta(1) was detected in spleen and lymph nodes of the allogeneic recipients for 3 weeks after TGF-beta-DC infusion, indicating that microchimerism of TGF-beta-DC is exhibited in allogeneic recipients. In this murine cervical heterotopic heart transplantation model, the survival of the allograft in recipients intravenously infused with TGF-beta-DC 7 days before transplantation was greatly prolonged, and about 67% of cardiac grafts survived more than 40 days. Histological analysis of the allografts showed that the normal myocardial architecture was well preserved, accompanied by very little necrotic cells, but interstitial fibrosis replaced myocytes, and moderate collagen suffused the whole cardiac allograft in the recipients infused with TGF-beta-DC. mRNA expression of type III procollagen was markedly increased in the allografts of the recipients infused with TGF-beta-DC. Our results suggest that infusion of TGF-beta(1) gene modified immature DC prolongs the survival of the allograft through the effective induction of donor-specific T cell hyporesponsiveness. However, TGF-beta(1) expressed by gene modified immature DC can cause the fibrosis of the allografts, which may limit the application of this approach in the allograft transplantation.