B cells and tumor immune escape / 中南大学学报(医学版)

B lymphocyte is an important component of the human immune system and it has a role in the process of the body's specific immunity. In recent years, the research on B cells and tumor immune escape has rapidly progressed. Studies have shown that different types of B cells play different roles in tumor microenvironment through a variety of mechanisms. B cells in the tertiary lymphatic structure promote anti-tumor immunity, while regulatory B cells promote tumor immune escape. Antibody drugs targeting B cells are a promising direction for tumor immunotherapy.

Multi-target combinatory strategy to overcome tumor immune escape / 医学前沿

Immune therapy has become the fourth approach after surgery, chemotherapy, and radiotherapy in cancer treatment. Many immune checkpoints were identified in the last decade since ipilimumab, which is the first immune checkpoint inhibitor to cytotoxic T-lymphocyte associated protein 4, had been approved by the US Food and Drug Administration (FDA) for the treatment of unresectable or metastatic melanoma in 2011. The use of several antibody drugs that target PD1/PD-L1 for various cancer treatments has been approved by the FDA. However, fewer people are benefitting from immune checkpoint inhibitor treatment in solid cancers. Approximately 80% of patients do not respond appropriately because of primary or acquired therapeutic resistance. Along with the characterization of more immune checkpoints, the combinatory treatment of multiimmune checkpoint inhibitors becomes a new option when monotherapy could not receive a good response. In this work, the author focuses on the combination therapy of multiple immune checkpoints (does not include targeted therapy of oncogenes or chemotherapy), introduces the current progression of multiple immune checkpoints and their related inhibitors, and discusses the advantages of combination therapy, as well as the risk of immune-related adverse events.

Immunotherapy in Head and Neck Squamous Cell Cancer

Prognosis in relapsed metastatic head and neck squamous cell cancer (RM-HNSCC) is dismal. Platinum based chemotherapy in combination with Cetuximab is used in first-line setting, while no further validated options are available at progression. Immunotherapy has produced durable clinical benefit in some patients with RM-HNSCC although the premises are several patients are nonresponders. Studies are ongoing to determine predictive factors and the ideal setting/combination of novel immunotherapies. In this paper, we discuss the past and present of immunotherapy in head and neck cancer and provide an up-to-date information regarding the potential ways to improve immunotherapy outcomes in HNSCC.

Immunological-based approaches for cancer therapy

The immunologic landscape of tumors has been continuously unveiled, providing a new look at the interactions between cancer cells and the immune system. Emerging tumor cells are constantly eliminated by the immune system, but some cells establish a long-term equilibrium phase leading to tumor immunoediting and, eventually, evasion. During this process, tumor cells tend to acquire more mutations. Bearing a high mutation burden leads to a greater number of neoantigens with the potential to initiate an immune response. Although many tumors evoke an immune response, tumor clearance by the immune system does not occur due to a suppressive tumor microenvironment. The mechanisms by which tumors achieve the ability to evade immunologic control vary. Understanding these differences is crucial for the improvement and application of new immune-based therapies. Much effort has been placed in developing in silico algorithms to predict tumor immunogenicity and to characterize the microenvironment via high-throughput sequencing and gene expression techniques. Each sequencing source, transcriptomics, and genomics yields a distinct level of data, helping to elucidate the tumor-based immune responses and guiding the fine-tuning of current and upcoming immune-based therapies. In this review, we explore some of the immunological concepts behind the new immunotherapies and the bioinformatic tools to study the immunological aspects of tumors, focusing on neoantigen determination and microenvironment deconvolution. We further discuss the immune-based therapies already in clinical use, those underway for future clinical application, the next steps in immunotherapy, and how the characterization of the tumor immune contexture can impact therapies aiming to promote or unleash immune-based tumor elimination.

Acarbose versus trans-chalcone: comparing the effect of two glycosidase inhibitors on obese mice

Objective Acarbose and trans-chalcone are glucosidase inhibitors whose beneficial effects have been demonstrated in diabetes. The present study aimed at investigating their potential effects in obesity.Materials and methods NMRI male mice (n = 48) were subjected to a high fat diet for four weeks, which induced an initial state of obesity. One control group was given normal rodent diet. Obese animals were then switched to normal rodent diet, and divided to four groups (n = 12 in each): untreated, sham (receiving grape seed oil), and experimental groups receiving acarbose and trans-chalcone (12 mg/kg) during eight weeks. Body weight, blood glucose and other biochemical parameters including triglycerides (TG), cholesterol, HDL, AST, and ALT were measured, as well as leptin, adiponectin, TNF-α, and total antioxidant capacity (TAC). Histological studies were performed on adipose cells and liver tissue samples.Results All factors were affected in a positive manner by acarbose, save for body weight, blood sugar and leptin levels, on which acarbose effects, although observable, were not statistically significant. Grape seed oil, used as a solvent for trans-chalcone was found to possess significant effect on TG and TAC, and had beneficial effects on other factors including liver enzymes and cholesterol. Trans-chalcone effects were significant on HDL, leptin and ALT. All compounds seemed to be able to affect fat deposition in liver tissue, and decrease the size of adipose tissue cells to some extent.Conclusion In conclusion, the tested compounds were able to affect lipid accumulation in tissues and influence adipokines, which may result in an enhanced state with regard to inflammation and oxidative stress. Arch Endocrinol Metab. 2015;59(3):202-9.

Associations of HLA gene with leukemia in 1186 cases / 中国实验血液学杂志

The purpose of this study was to evaluate the potential associations between HLA-A, B, DRB1 gene and leukemia. A total of 1186 leukemic patients, including 326 patients with acute lymphoblastic leukemia (ALL), 545 patients with acute myeloid leukemia (AML), 315 patients with chronic myeloid leukemia (CML), and 1234 healthy unrelated donors were typed and were compared in a single centre by using same technique, then the Bonferroni correction method was used to correct the Type I error. The results indicated that as compared with the control,the frequency of HLA-DRB1(*)09 in ALL group significantly decreased (10.87% versus 16.08%; Pc = 0.014, OR = 0.637, 95% CI = 0.487-0.834), while in comparison with control, the frequency of HLA-B(*)18 in CML group was significantly higher (1.28% vs 0.20%; Pc = 0.039, OR = 6.336, 95% CI = 2.066-19.434). The positive and negative relation may exist between certain HLA molecules and leukemia. The negative relation between HLA-DRB1(*)09 and ALL indicated that DRB1*09 might play an important role by a restricted T-cell immune response in the early leukemogenic events, whereas the positive relation between HLA-B(*)18 and CML suggests that the B(*)18 molecules may not actively present leukemia-specific antigens resulting in immune escape. It is concluded that these findings can contribute to developing more appropriate method in leukemic immunotherapy.

Effect of soluble PD-L1 released by lung cancer cells in regulating the function of T lymphocytes / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To explore the expression of soluble programmed death ligand-1 on lung cancer cells and to clarify its biological function through PD-1/PD-L1 pathway in regulating the function of T lymphocytes.</p><p><b>METHODS</b>Labeled monoclonal antibody and flow cytometry were used to analyze the expression of PD-L1 and its receptor PD-l on lung cancer cells and human T lymphocytes, respectively. The level of sPD-L1 in the supernatant of lung cancer cells was determined with an ELISA kit. The inhibition of proliferation of T lymphocytes by mPD-L1 and sPD-L1 was studied using CCK-8 incorporation.</p><p><b>RESULTS</b>Low or no expression [(16.08 ± 2.28)%] of PD-1 was found on resting T lymphocytes from human peripheral blood with flow cytometry, but up-regulated expression of PD-1 [(78.06 ± 7.21)%] was found on the surface of activated T lymphocytes. Soluble PD-L1 was found in supernatant of some lung cancer cell lines, such as H1299, HO8910, SPCA-1, H460, H446 cells, with PD-L1 expressing on their cell surface [(78.34 ± 10.25)%, (68.17 ± 11.56)%, (45.32 ± 7.98)%, (47.52 ± 9.62)% and (40.95 ± 8.56)%, respectively], but very low expression on A549 cells [(16.02 ± 6.28)%]. The level of mPD-L1 on H1299 cells was highest [(78.34 ± 10.25)%], compared with HO8910 cells (68.17 ± 11.56)%, SPCA-1 cells (45.32 ± 7.98)%, H446 cells (40.95 ± 8.56)%, and H460 cells (47.52 ± 9.62)%. At the same time, the sPD-L1 level on H1299 cells was low [(0.17 ± 0.01) ng/ml], compared with HO8910 cells (0.30 ± 0.03) ng/ml, SPCA-1cells (0.59 ± 0.03) ng/ml, H446 cells (0.34 ± 0.02) ng/ml, and H460 cells (0.57 ± 0.03) ng/ml, but not expressed on A549 cells. PD-L1 expressing H1299 cells inhibited the proliferation of T lymphocytes in the co-culture system. Supernatant of the cultured PD-L1(+) lung cancer cells also inhibited T cell proliferation. Anti-human PD-L1 blocking antibody could partly restore the proliferation capacity of T lymphocytes.</p><p><b>CONCLUSIONS</b>Membrane-bound PD-L1 and soluble PD-L1 released from lung cancer cells can effectively inhibit the proliferation of T lymphocytes in mixed culture system and down-regulate cell-mediated immunity in vitro. This may lead to inactivation of tumor antigen-specific T cells and immune escape of lung cancer cells.</p>

K562 cells induces apoptosis of activated NK cells in vitro / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the apoptosis of NK cells induced by the erythroleukemia cell line K562 in vitro.</p><p><b>METHODS</b>Primary NK cells isolated from the peripheral blood of healthy donors by magnetic-activated cell sorting were cultured with stem cell medium containing recombinant human interleukin-2 (rhIL-2). The NK cells and K562 cells were mixed and co-cultured at different E:T ratios for different time lengths. The apoptosis of NK cells and K562 cells were detected using PE-AnnexinV/7-AAD labeling and flow cytometry.</p><p><b>RESULTS</b>The purity of isolated NK cells reached (93.99∓4.22)%. At the same E: T ratio, the apoptotic rate of NK cells induced by K562 cells increased significantly with time. As the E:T ratio reduced, the apoptotic rate of the NK cells increased and their cytotoxic activity against K562 cells was attenuated.</p><p><b>CONCLUSION</b>K562 cells can induce the apoptosis of activated NK cells, which is one of the probable mechanisms of immune escape of tumors.</p>

Carcinogénesis

La división celular es controlada por una serie de sistemas que tienen efectos estimulantes o inhibitorios.El cáncer es de origen monoclonal, y para que una célula normal cambie su fenotipo y se convierta en una célula neoplásica deben ocurrir mutaciones genéticas en la misma.Dichas mutaciones genéticas ocasionan la modificación de los productos que en condiciones normales codificaría el gen y,finalmente,a un cáncer.El cáncer resultante puede ser hereditario (por mutaciones en uno o ambos alelos de las células germinales) o esporádico (por la acción de agentes mutágenos ambientales).A su vez, los mecanismos que pueden conducir a alteraciones en los genes pueden ser genéticos o epigenéticos; los primeros se presentan ante alteraciones estructurales del genoma y los restantes, epigenéticos, por alteraciones de las enzimas o de los sustratos de las mismas.La carcinogénesis consta de tres etapas:iniciación,promoción y progresión.La última de estas etapas,progresión,es exclusiva de la transformación maligna e implica la capacidad de invadir tejidos vecinos o a distancia. Para que se lleve a cabo el proceso metastásico, se requiere de una serie de mecanismos: angiogénesis, degradación de matrices, migración celular, evasión de la respuesta inmune del hospedero y colonización metastásica. Este artículo representa una revisión parcial de la bibliografía actualizada de los conceptos relacionados a la carcinogénesis y la información mínima necesaria para lograr un entendimiento de este complejo proceso.

Cell division is controlled by stimulatory and inhibitory systems.The origin of cancer is monoclonal, and in order that a normal cell switches its phenotype and becomes a neoplastic cell, genetic mutations must occur on it.These genetic mutations modify the products that in normal conditions the gene would codify and, finally, cause cancer. Cancer may be hereditary (due to mutations in one or both of germinal cells alleles) or sporadic (due to action of environmental mutagenic agents).The mechanisms that may cause alterations on genes may be genetic or epigenetic. Genetic mechanisms occur when structural alterations of genome are present and the epigenetic processes occur due to enzymatic alterations or alterations on its substrates. Carcinogenesis has three stages: initiation, promotion and progression.The last of these stages, progression, is exclusive of malignant transformation and implies the capacity to invade surrounding or distant tissues. For metastasis to take place, many mechanisms are required: angiogenesis, matrix degradation, cell migration, evasion of host immune response and metastatic colonization. This article presents a partial review of current bibliography about concepts related to carcinogenesis and conveys the minimum necessary information to achieve an understanding of this complex process.

Relationship between MAP3K5 and Epstein-Barr virus-encoded miR-BART22 expression in nasopharyngeal carcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To detect the expression of MAP3K5 and miR-BART22 encoded by Epstein-Barr virus and explore their relationship in nasopharyngeal carcinomas (NPCs).</p><p><b>METHODS</b>Fifty-three archived specimens of NPCs and 30 nasopharyngitis specimens were collected for detecting the expression of EBERs and miR-BART22 by in situ hybridization, and the expression of MAP3K5 was detected using immunohistochemistry. Ten fresh NPC and 10 fresh nasopharyngitis specimens were also obtained for determining the protein expression of MAP3K5 by Western blotting.</p><p><b>RESULTS</b>EBERs were positive in all the 53 NPC specimens, and miR-BART22 was positive in 49 specimens; all the 30 nasopharyngitis specimens were negative for EBER or miR-BART22. In the 53 NPC tissues, 50 were negative for MAP3K5 expression in the cancer areas but positive in the adjacent mucosal areas, with the other 3 specimens showing a weak positivity (+). In the 30 nasopharyngitis specimens, 25 showed strong MAP3K5 positivity, 3 showed weak positivity and 2 were negative for MAP3K5 (P<0.001). Western blotting showed that the expression of MAP3K5 protein was significantly higher in nasopharyngitis than in NPC tissues (P=0.029). The expression of MAP3K5 and miR-BART22 was inversely correlated (P<0.001).</p><p><b>CONCLUSION</b>Compared with the adjacent mucosal tissues, NPC tissues have a lower expression of MAP3K5 but a higher expression of miR-BART22. The expression of MAP3K5 and miR-BART22 is inversely correlated, suggesting the possibility of MAP3K5 to serve as target gene of EBV miR-BART22. miR-BART22 may inhibit the expression of MAP3K5, thus reducing the protein phosphorylation of MAPK pathway downstream genes, inhibiting NPC cell apoptosis, preventing their differentiation and promoting their escape from immune surveillance.</p>

Apoptosis and expression of Fas/FasL in tumor infiltrating dendritic cells in human endometrioid adenocarcinoma / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate apoptosis of tumor infiltrating dendritic cells (TIDC) and their expression of Fas/FasL (CD95/CD95L) in human endometrioid adenocarcinoma.</p><p><b>METHODS</b>The apoptotic rate of TIDC was measured in 45 cases of endometrioid adenocarcinoma and 20 cases of normal endometrium tissues (control) by double-label immunohistochemistry using the monoclonal antibody S-100 protein and TUNEL technique. The expressions of Fas and FasL in TIDCs were detected using double-label immunohistochemistry and imaging analysis.</p><p><b>RESULTS</b>The apoptotic rate of TIDCs in endometrioid adenocarcinoma were significantly higher than that in normal endormetrium [(13.02∓0.64)% vs (6.82∓0.53)%, P<0.05]. The expression levels of Fas in the TIDCs were significantly lower, whereas FasL expression significantly higher in endometrioid adenocarcinoma than in normal endormetrium (7.88∓1.05 vs 19.25∓3.03, P<0.05; 12.95∓2.25 vs 7.51∓1.14, P<0.05).</p><p><b>CONCLUSION</b>Increased apoptosis of the TIDCs and abnormal expression of Fas/FasL in TIDCs in endometrioid adenocarcinoma may lead to tumor immune escape.</p>

Inmunoterapia del cáncer: Importancia de controlar la inmunosupresión / Cancer immunotherapy: Importance of overcoming immune suppression

Es cada vez mayor la evidencia experimental y clínica de que el sistema inmunitario interviene activamente en la patogénesis y el control de la progresión tumoral. Una respuesta antitumoral efectiva depende de la correcta interacción de varios componentes del sistema inmunitario, como las células presentadoras de antígeno y diferentes sub-poblaciones de linfocitos T. Sin embargo, los tumores malignos desarrollan numerosos mecanismos para evadir el reconocimiento y su eliminación por parte del sistema inmunitario. En esta revisión discutiremos algunos de esos mecanismos y posibles estrategias terapéuticas para contrarrestarlos.

Increasing evidence indicates that the immune system is involved in the control of tumor progression. Effective antitumor immune response depends on the interaction between several components of the immune system, including antigen-presenting cells and different T cell subsets. However, tumor cells develop a number of mechanisms to escape recognition and elimination by the immune system. In this review we discuss these mechanisms and address possible therapeutic approaches to overcome the immune suppression generated by tumors.

Dissecando os caminhos de escape do tumor: "uma questão de vida e morte?" / Dissecting the pathways of tumour escape: "a question of life and death?"

Apoptotic pathways are providing important saveguard mechanisms in protection from cancer by eliminating altered and often harmful cells. The disturbances of cell proliferation, differentiation and apoptosis are also found on specific signal-transduction pathways within the tumour cells and between these and the immune system. The article focuses attention on the evolution of the melanocytic naevi in the direction of a dysplastic or tumour cell. The determination of single molecules as prognostic parameters within cancer genesis seems to be problematic. New hopes are being placed on the treatment with TW-37, ABT-737 and TAT-Bim, which, to an extent, are able to support the programmed cell death. The clinical importance of these innovative therapies remains to be seen and should therefore, be viewed with considerable criticism.

Caminhos apoptóticos estão fornecendo importantes mecanismos de salvaguarda na proteção contra o câncer através da eliminação de células alteradas e freqüentemente nocivas.Os distúrbios de proliferação, diferenciação e apoptose celular são também encontrados nos caminhosespecíficos sinal-transdução dentro das células tumor e entre essas células e o sistema imunitário. O artigo foca na evolução da verruga conhecida como melanocytic naevi em direção a uma célula displasica ou célula tumor. A determinação de moléculas isoladas como parâmetros de prognóstico dentro da gênesis do câncer parece problemática. Novas esperanças estão sendo colocadas no tratamento com TW-37, ABT-737 e TAT-Bim, os quais, até certo ponto, são aptos a apoiar a morte celular programada (PCD). A importância clínica dessas terapias inovadoras permanece ainda a ser vista e devem, por essa razão, seremolhadas com considerável juízo crítico.

Expression and abscission of activated receptors and their ligands on/from NK cells in peripheral blood of patients with acute leukemia / 中国实验血液学杂志

This study was aimed to explore the immune escaping mechanisms based on expression and abscission of human natural killer (NK) cell activating receptors NKG2D and their ligands MICA/B, ULBP-1, 2, 3 in patients with acute leukemia (AL). 30 de novo AL patients and 10 healthy persons (control) were enrolled in study. Flow cytometry was used to detect the expression levels of MICA/B, ULBP-1, 2, 3 on leukemic cells. ELISA was used to detect the levels of soluble MICA (sMICA), solube MICB (sMICB) and soluble ULBP-1, -2, -3 in the serum. The results showed that sMICA, sMICB and ULBP-1, -2, -3 were not expressed or expressed at very low levels on leukemia cells of the patients; the levels of free sMICA and sMICB in serum of AL patients were higher than that in serum of healthy persons, there was significant difference (p<0.01). But the levels of ULBP 1-3 in serum of AL patients did not show obvious statistical difference as compared with healthy persons (p>0.05). It is concluded that the negative or low expression of NKG2D ligands (MICA, MICB and ULBPs) on surface of acute leukemia cells may lead to the immune escape of leukemia cells, the abscission of MICA and MICB, and the deficiency of ULBP expression on leukemia cells may be one of immune escape mechanisms of leukemia cells.

Correlation of Fas/FasL expression to cell apoptosis in Epstein-Barr virus-associated gastric carcinoma / 癌症

<p><b>BACKGROUND AND OBJECTIVE</b>Epstein-Barr virus (EBV) has been detected in about 10% of gastric carcinomas. However, the pathogenetic role of EBV in gastric carcinoma is uncertain. This study was to explore the correlation of Fas/FasL expression to the apoptosis of tumor cells and tumor-infiltrating lymphocytes (TIL) in EBV-associated gastric carcinoma (EBVaGC).</p><p><b>METHODS</b>Fas/FasL expression in 49 specimens of EBVaGC, 20 specimens of EBV-negative gastric carcinoma (EBVnGC) and 12 specimens of normal gastric mucosa was detected by immunohistochemistry. The apoptotic index (AI) of cells was determined by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL).</p><p><b>RESULTS</b>The positive rates of Fas were 91.7% in normal gastric mucosa and 76.8% in gastric carcinoma (P < 0.05); those of FasL were 16.7% in normal gastric mucosa and 58% in gastric carcinoma (P < 0.05). The positive rate of Fas was significantly lower in EBVaGC than in EBVnGC (71.4% vs. 90.0%, P < 0.05). The positive rate of FasL in EBVaGC was significantly higher than that in EBVnGC (63.2% vs. 45%, P < 0.05). The AI of EBVaGC cells was significantly lower than that of EBVnGC cells (P = 0.002). The number and AI of TIL in EBVaGC were higher than those in EBVnGC (P < 0.05). The AI of TIL was positively correlated with the level of FasL expression in tumor cells (r=0.237, P = 0.028).</p><p><b>CONCLUSION</b>Up-regulation of FasL expression and decrease of TIL apoptosis in EBVaGC may facilitate the escape of tumor cells from the host immunosurveillance, and it might contribute to the development and progression of carcinoma.</p>

Effect of polypeptide extract from scorpion venom (PESV) on immune escape of Lewis lung carcinomas / 中国中药杂志

<p><b>OBJECTIVE</b>To study the effects of polypeptide extract from scorpion venom (PESV) on immune escape of Lewis lung carcinomas (LLC) and its mechanism.</p><p><b>METHOD</b>Forty C57BL/6J mice were inoculated with LLC cells suspension (1 x 10(7) cells/ mL) in right armpit subcutaneously. The tumor-bearing mice were randomly divided into two groups: the control group and the PESV group. PESV was intragastrically subjected to the mice of the experimental group for 18 days. The tumor volume and tumor inhibitory rate were determined. The expression levels of VEGF,TGF-beta1 and IL-10 in tumor microenvironment were determined by immunohisto-chemistry-staining and ELISA. Surface co-stimulatory molecules CD80 and CD86 of tumor infiltrating dendritic cells (DC) were determined by immunohistochemistry-staining and flow cytometry.</p><p><b>RESULT</b>The growth inhibitory rate of PESV was 56. 60%. The expression levels of VEGF,TGF-beta1 and IL-10 were decreased in tumor and serum, while the expression of co-stimulatory molecules CD80 and CD86 on DC were increased in tumor. Compared with the control group, the differences were all significant (P < 6.05).</p><p><b>CONCLUSION</b>PESV was effective in recovering immuno-surveillance and intervening immune escape of lung cancer through multi-pathway. And its effects might be attained by decreasing the level of VEGF, TGF-beta1 and IL-10 in tumor microenvironment and increasing the expression of co-stimulatory molecules CD80 and CD86 on DC.</p>

Effects of Sema3A derived from tumor cells on functions of dendritic cells / 浙江大学学报·医学版

<p><b>OBJECTIVE</b>To investigate the effects of tumor cell-derived Sema3A on the immunological functions of murine dendritic cells (DCs).</p><p><b>METHODS</b>Lung adenocarcinoma A549 cells were transfected with small interference RNA, Si-Sema and Si-mut, and the interference efficiency was determined by real-time PCR and Western-blot. The concentrated supernatants from cultured tumor cells, Si-Sema and Si-mut-infected tumor cells were subjected to DCs respectively. The immunophenotypes of DCs were analyzed by flow cytometry, the production of IL-12P70 and the ability of DCs to stimulate DO11. 10 T cells secreting IFN-gamma and IL-2 were detected by enzyme linked immunosorbent assay (ELISA).</p><p><b>RESULTS</b>Knockdown with Si-Sema3A significantly decreased the secretion of Sema3A by A549 cells in comparison with the Si-mut cells. DCs exposed to supernatants from Si-Sema cells showed elevated levels of MHC, CD40 and CD80, more production of IL-12P70, and enhanced capability of activating antigen-specific T cells, as evidenced by the remarkably increased levels of IFN-gamma and IL-2.</p><p><b>CONCLUSION</b>A549 cells secrete Sema3A to inhibit the maturation and functions of DCs, which might be associated with the unidentified mechanism of immune evasion by tumor cells.</p>

Tumour-derived exosomes and their roles in cancer / 中南大学学报(医学版)

Exosomes are nanometer sized membrane vesicles, released in the extracellular milieu following the fusion of the external membrane of multivesicular body (MVB) with plasma membrane. They perform a certain function in immune regulation. Exosomes have been shown to be released by cells of hematopoietic and non-hematopoietic origin. Tumour-derived exosomes (TEX) exist in the supernatant of tumour cells, plasma and malignant effusions of tumour patients. They contain native candidate tumour associated antigen and are capable of transferring antigens to T lymphocytes, therefore efficiently promoting cytotoxic T lymphocyte (CTL) activation and producing antitumor immunity. However, recent evidence shows that tumor exosomes may induce immunologic tolerance and even activate immunosuppression which makes tumour escape from the immune surveillance of the host immune system. In addition, tumor exosomes may mediate a growth-promoting effect on tumor cells. These discrepancies are almost certainly due to differences in the phenotype of the exosomes.

Ressecção alargada para o adenocarcinoma colorretal localmente invasivo: relato de caso e revisão da literatura / Enlarged resection for locally advanced colorectal adenocarcinoma: case report and literature review

O câncer colorretal localmente invasivo, que acomete por contiguidade estruturas adjacentes e sem metástases à distância, ocorre de 5 a 18% dos casos. São adequadamente tratados com ressecção do tumor e órgãos comprometidos em monobloco e margens livres. É relatado o caso de paciente de 27 anos, masculino, portador de adenocarcinoma de retossigmóide com extensa invasão para bexiga e ceco. Tratado com colectomia total, cistectomia radical em monobloco e ileostomia. O trânsito urinário foi reconstituído com reservatório ileal e anastomose com a uretra prostática. O estudo anátomo-patológico da peça cirúrgica revelou adenocarcinoma moderadamente diferenciado, invasão perineural e invasão da parede da bexiga (T4, N0). Realizou no pós-operatório quimioterapia adjuvante, 6 ciclos, com 5-Fluorouracil e ácido folínico. Após 36 meses de seguimento, o paciente encontra-se livre de doença neoplásica, função urinária preservada, porém com ejaculação retrógrada.

The locally advanced colorectal cancer compromises adjacent structures and do not disseminate distant metastasis, occur in 5 to 18% of patients. It is properly treated with tumour resection as well as other compromised organs in an "en bloc" resection with free margins. We report a 27 year old, male patient with colorectal adenocarcinoma invading the urinary bladder and cecum. He was treated with total colectomy associated with radical cistectomy and ileostomy. The urinary transit was established building an ileal reservatory anastomosed to the urethra. The tumour histopathologic study showed adenocarcinoma moderate differentiated, invading urinary bladder (T4N0). Postoperative treatment was 5-fluorouracil and folinic acid chemotherapy. After 36 months of outcome, patient is improving and preserves urinary function but has ejaculatory dysfunction.

Costimulatory molecule B7-H1 on the immune escape of bladder cancer and its clinical significance / 华中科技大学学报（医学）（英德文版）

B7-H1, a recently described member of the B7 family of costimulatory molecules, is thought to be involved in tumor immune escape by inducing T-cell apoptosis. In order to investigate the relationship between B7-H1 and immune escape of bladder cancer, B7-H1 expression in 50 cases of bladder cancer was detected by using immunohistochemical method. Survival curves were constructed using the Kaplan-Meier method and independent prognostic factors were evaluated using the Cox regression model. Our results showed that the positive rate of B7-H1 immunostaining in normal bladder tissue and bladder cancer was 0 and 72% respectively. The expression of B7-H1 was strongly associated with the pathological grade, clinical stage and recurrence (P<0.05). The survival rate was significantly lower in patients with B7-H1 positive group than in those with B7-H1 negative group and multi-variable analysis revealed that B7-H1 could be regarded as an independent factor in evaluating the prognosis of bladder cancer. It is concluded that the expression of B7-H1 is strongly associated with neoplastic progression and prognosis of bladder cancer. The manipulation of B7-H1 may become a beneficial target for immunotherapy in human bladder cancer.