CLDN11在胰腺癌神经浸润动物模型中mRNA水平的表达

目的:神经浸润的发生预示胰腺癌预后不良,疼痛的发生与神经浸润密切相关,癌细胞和神经组织间相互作用、连接及粘附可能参与了神经浸润的发生,Claudins作为组成紧密连接的主要成份,在多种肿瘤中有所表达,本实验拟通过观察其成员CLDN11在体内、体外mRNA水平的表达,探讨CLDN11在胰腺癌神经浸润发病机制中的作用,为其诊断及治疗新方法的探索提供一定的实验依据。方法:通过裸鼠坐骨神经周围注射不同人胰腺癌细胞系的方法建立稳定的胰腺癌神经浸润动物模型,成瘤后检测肿瘤组织中CLDN11 mRNA表达水平的差异。同时检测不同人胰腺癌细胞株中CLDN11 mRNA的表达水平的差异。结果:CLDN11在神经侵犯发生率低的肿瘤中的表达高于神经侵犯发生率高的肿瘤,在正常胰腺组织中无表达。CLDN11的mRNA水平在panc-1细胞株中表达高于Capan-2组。结论:经本实验研究发现CLDN11在PNI发生率高的肿瘤组织及高神经浸润能力的细胞株中表达下调,而在PNI发生率低的肿瘤组织及神经浸润能力低的细胞株中高表达,可以得出在神经浸润发生中,CLDN11的表达受到抑制的结论,由此推断如果过表达CLDN11,有可能阻碍PNI的发生及发展;另外,CLDN11表达的下降也可能预示着PNI的发生及进展,因此CLDN11表达的下降可作为PNI发生的预警信号,也可作为胰腺癌基因治疗的靶点,为提高胰腺癌的早期诊断率、改善胰腺癌的预后提供初步的基础实验依据。     

Inhibitory Effect of Tumor Suppressor p53 on Proinflammatory Chemokine Expression in Ovarian Cancer Cells by Reducing Proteasomal Degradation of IκB

Ovarian cancer, one of inflammation-associated cancers, is the fifth leading cause of cancer deaths among women. Inflammation in the tumor microenvironment is associated with peritoneal tumor dissemination and massive ascites, which contribute to high mortality in ovarian cancer. Tumor suppressor p53 is frequently deleted or mutated in aggressive and high-grade ovarian cancer, probably aggravating cancer progression and increasing mortality. We therefore investigated the influence of p53 on proinflammatory chemokines in ovarian cancer cells. A PCR array of the chemokine network revealed that ovarian cancer cells with low or mutated p53 expression expressed high levels of proinflammatory chemokines such as CXCL1, 2, 3 and 8. Transient transfection of p53 into p53-null ovarian cancer cells downregulated proinflammatory chemokines induced by tumor necrosis factor-α (TNF), a proinflammatory cytokine abundantly expressed in ovarian cancer. Furthermore, p53 restoration or stabilization blocked TNF-induced NF-κB promoter activity and reduced TNF-activated IκB. Restoration of p53 increased ubiquitination of IκB, resulting from concurrently reduced proteasome activity followed by stability of IκB. A ubiquitination PCR array on restoration of p53 did not reveal any significant change in expression except for Mdm2, indicating that the balance between p53 and Mdm2 is more important in regulating NF-κB signaling rather than the direct effect of p53 on ubiquitin-related genes or IκB kinases. In addition, nutlin-3, a specific inducer of p53 stabilization, inhibited proinflammatory chemokines by reducing TNF-activated IκB through p53 stabilization. Taken together, these results suggest that p53 inhibits proinflammatory chemokines in ovarian cancer cells by reducing proteasomal degradation of IκB. Thus, frequent loss or mutation of p53 may promote tumor progression by enhancing inflammation in the tumor microenvironment.     

Competitive enhancement of HGF-induced epithelial scattering by accessory growth factors

HGF signaling induces epithelial cells to disassemble cadherin-based adhesion and increase cell motility and invasion, a process termed epithelial–mesenchymal transition (EMT). EMT plays a major role in cancer metastasis, allowing individual cells to detach from the primary tumor, invade local tissue, and colonize distant tissues with new tumors. While invasion of vascular and lymphatic networks is the predominant route of metastasis, nerves also can act as networks for dissemination of cancer cell to distant sites in a process termed perineual invasion (PNI). Signaling between nerves and invasive cancer cells remains poorly understood, as does cellular decision making that selects the specific route of invasion. Here we examine how HGF signaling contributes to PNI using reductionist culture model systems. We find that TGFβ, produced by PC12 cells, enhances scattering in response to HGF stimulation, increasing both cell–cell junction disassembly and cell migration. Further, gradients of TGFβ induce migratory mesenchymal cells to undergo chemotaxis towards the source of TGFβ. Interestingly, VEGF suppresses TGFβ-induced enhancement of scattering. These results have broad implications for how combinatorial growth factor signaling contributes to cancer metastasis, suggesting that VEGF and TGFβ might modulate HGF signaling to influence route selection during cancer progression.     

Colon carcinoma cells induce CXCL11-dependent migration of CXCR3-expressing cytotoxic T lymphocytes in organotypic culture

Adoptive immunotherapy of cancer patients with cytolytic T lymphocytes (CTL) has been hampered by the inability of the CTL to home into tumors in vivo. Chemokines can attract T lymphocytes to the tumor site, as demonstrated in animal models, but the role of chemokines in T-lymphocyte trafficking toward human tumor cells is relatively unexplored. In the present study, the role of chemokines and their receptors in the migration of a colon carcinoma (CC) patient’s CTL toward autologous tumor cells has been studied in a novel three-dimensional organotypic CC culture. CTL migration was mediated by chemokine receptor CXCR3 expressed by the CTL and CXCL11 chemokine secreted by the tumor cells. Excess CXCL11 or antibodies to CXCL11 or CXCR3 inhibited migration of CTL to tumor cells. T cell and tumor cell analyses for CXCR3 and CXCL11 expression, respectively, in ten additional CC samples, may suggest their involvement in other CC patients. Our studies, together with previous studies indicating angiostatic activity of CXCL11, suggest that CXCL11 may be useful as an immunotherapeutic agent for cancer patients when transduced into tumor cells or fused to tumor antigen-specific Ab.     

Role of glial cell line-derived neurotrophic factor in perineural invasion of pancreatic cancer

Perineural invasion (PNI) is the initial infiltration of tumor cells into the retroperitoneal nerve plexus and along the nerves. It precludes curative resection, is thought to be the major cause of local recurrence following resection, and is a special metastatic route in pancreatic cancer. Glial cell line-derived neurotrophic factor (GDNF) was recently recognized as a key player in the PNI process. This review covers the most recently published studies on the role of GDNF in pancreatic cancer. We introduce the players in PNI, summarize the distribution of GDNF and its receptors in pancreatic cancer, and discuss the effects and underlying mechanism of GDNF in the PNI process. Finally, we also review some potential inhibitors for GDNF-targeted therapy.     

CXC chemokine ligand 12 (stromal cell-derived factor 1 alpha) and CXCR4-dependent migration of CTLs toward melanoma cells in organotypic culture

Studies in experimental animal models have demonstrated that chemokines produced by tumor cells attract chemokine receptor-positive T lymphocytes into the tumor area, which may lead to tumor growth inhibition in vitro and in vivo. However, in cancer patients, the role of chemokines in T lymphocyte trafficking toward human tumor cells is relatively unexplored. In the present study, the role of chemokines and their receptors in the migration of a melanoma patient's CTL toward autologous tumor cells has been studied in a novel organotypic melanoma culture, consisting of a bottom layer of collagen type I with embedded fibroblasts followed successively by a tumor cell layer, collagen/fibroblast separating layer, and, finally, a top layer of collagen with embedded fibroblasts and T cells. In this model, CTL migrated from the top layer through the separating layer toward tumor cells, resulting in tumor cell apoptosis. CTL migration was mediated by chemokine receptor CXCR4 expressed by the CTL and CXCL12 (stromal cell-derived factor 1alpha) secreted by tumor cells, as evidenced by blockage of CTL migration by Abs to CXCL12 or CXCR4, high concentrations of CXCL12 or small molecule CXCR4 antagonist. These studies, together with studies in mice indicating regression of CXCL12-transduced tumor cells, followed by regression of nontransduced challenge tumor cells, suggest that CXCL12 may be useful as an immunotherapeutic agent for cancer patients, when transduced into tumor cells, or fused to anti-tumor Ag Ab or tumor Ag.     

Dedifferentiated Schwann cells promote perineural invasion mediated by the PACAP paracrine signalling in cervical cancer

Perineural invasion (PNI) has emerged as a key pathological feature and be considered as a poor prognostic factor in cervical cancer. However, the underlying molecular mechanisms are largely unknown. Here, PNI status of 269 cervical squamous cell carcinoma and endocervical adenocarcinoma (CESC) samples were quantified by using whole-slide diagnostic images obtained from The Cancer Genome Atlas. Integrated analyses revealed that PNI was an indicative marker of poorer disease-free survival for CESC patients. Among the differentially expressed genes, ADCYAP1 were identified. Clinical specimens supported that high expression of PACAP (encoded by ADCYAP1) contributed to PNI in CESC. Mechanistically, PACAP, secreted from cervical cancer cells, reversed myelin differentiation of Schwann cells (SCs). Then, dedifferentiated SCs promoted PNI by producing chemokine FGF17 and by degrading extracellular matrix through secretion of Cathepsin S and MMP-12. In conclusion, this study identified PACAP was associated with PNI in cervical cancer and suggested that tumour-derived PACAP reversed myelin differentiation of SCs to aid PNI.     

The role of pretreatment prognostic nutritional index in esophageal cancer: A meta-analysis

Clinicopathological characteristics and prognosis of esophageal cancer (EC) patients with decreased prognostic nutritional index (PNI) have not been well investigated. So, we conducted this meta-analysis. We performed comprehensive research in PubMed, Embase, and Cochrane databases. The effect size was hazard ratio (HR) with 95% confidence interval (CI) for overall survival (OS) and cancer-specific survival (CSS). The pooled odds ratio (OR) with 95% CI were used to assess the association between PNI and clinicopathological features. A total of 3,425 EC patients were included in the present meta-analysis. Male patients, advanced age, higher tumor stage, and lymph node metastases were associated with reduced PNI level (OR = 1.40, 95% CI: 1.10-1.79; OR = 1.35, 95% CI: 1.10-1.66; OR = 2.37, 95% CI: 1.91-2.94; OR = 1.63, 95% CI: 1.04-2.56). And, the EC patients with decreased PNI held a worse OS and CSS compared with those who carried a higher PNI (HR = 1.29, 95% CI: 1.10-1.50; HR = 2.53, 95% CI: 1.15-5.57). This meta-analysis demonstrated PNI level was associated with tumor stage and lymph nodes metastases and was an independent prognostic factor in EC.     

Role of platelets and platelet receptors in cancer metastasis

The interaction of tumor cells with platelets is a prerequisite for successful hematogenous metastatic dissemination. Upon tumor cell arrival in the blood, tumor cells immediately activate platelets to form a permissive microenvironment. Platelets protect tumor cells from shear forces and assault of NK cells, recruit myeloid cells by secretion of chemokines, and mediate an arrest of the tumor cell platelet embolus at the vascular wall. Subsequently, platelet-derived growth factors confer a mesenchymal-like phenotype to tumor cells and open the capillary endothelium to expedite extravasation in distant organs. Finally, platelet-secreted growth factors stimulate tumor cell proliferation to micrometastatic foci. This review provides a synopsis on the current literature on platelet-mediated effects in cancer metastasis and particularly focuses on platelet adhesion receptors and their role in metastasis. Immunoreceptor tyrosine-based activation motif (ITAM) and hemi ITAM (hemITAM) comprising receptors, especially, glycoprotein VI (GPVI), FcγRIIa, and C-type lectin-like-2 receptor (CLEC-2) are turned in the spotlight since several new mechanisms and contributions to metastasis have been attributed to this family of platelet receptors in the last years.     

Chemokines in cancer

Chemokines participate, by regulating cell trafficking and controlling angiogenesis, in the host response during infection and inflammation. Most of these mechanisms are also operating in cancer. The stimulation of angiogenesis and tumor growth--directly or indirectly through the recruitment of tumor-associated macrophages--are typical situations where chemokines promote tumor development. On the other hand, chemokines could be used to the benefit of cancer patients as they act in the recruitment of dendritic cells (DC) or/and effector cells or for their angiostatic properties. However, chemokine-mediated recruitment of immature DC within tumors, due to factors produced by the tumor milieu, could lead to the induction of immune tolerance and, therefore, novel strategies to eradicate tumors based on chemokines should attempt to avoid this risk.     

The countercurrent principle in invasion and metastasis of cancer cells. Recent insights on the roles of chemokines

Chemokine production by cancer cells constitutes a duality. Leukocyte recruitment under the pressure of chemokines may be beneficial for the host or for the tumor. Here, the emphasis will be on the detrimental effects of chemokines in tumor biology. A decade ago, the countercurrent principle of tumor-derived chemokine and peritumoral protease production was formulated to explain chemokine expression as a selective advantage for specific tumors and as a phenotype of invasive and metastasizing cancer cells. Chemoattracted leukocytes may provide trophic factors and produce invasion and metastasis-promoting proteinases. On the basis of the consensus sequence glutamic acid-leucine-arginine (ELR) preceding the canonical cysteine-any amino acid-cysteine (CXC), ELR-positive CXC chemokines, such as interleukin-8 and granulocyte chemotactic protein-2, are angiogenic and thus instruct the host to feed the tumor and bring the vessels into closer contact with the tumor cells. These mechanisms may enhance lymphogenic and hematogenic metastasis. Recent research and proofs of this countercurrent concept are here reviewed and compared. In addition, we discuss how alterations in chemokine ligand and receptor expression profiles may contribute to tumor growth, invasion, metastasis and immune evasion. These comparisons imply practical consequences for future cancer diagnosis and therapy. The implications include methods to diminish metastasis by inhibiting angiogenic CXC chemokine ligands and receptors, therapeutic combinations of chemokine overexpression with antigenic stimuli and co-treatment with angiostatic chemokines and tumor antigens.     

P2X receptors: New players in cancer pain

Pain is unfortunately a quite common symptom for cancer patients. Normally pain starts as an episodic experience at early cancer phases to become chronic in later stages. In order to improve the quality of life of oncological patients, anti-cancer treatments are often accompanied by analgesic therapies. The P2X receptor are adenosine triphosphate (ATP) gated ion channels expressed by several cells including neurons, cancer and immune cells. Purinergic signaling through P2X receptors recently emerged as possible common pathway for cancer onset/growth and pain sensitivity. Indeed, tumor microenvironment is rich in extracellular ATP, which has a role in both tumor development and pain sensation. The study of the different mechanisms by which P2X receptors favor cancer progression and relative pain, represents an interesting challenge to design integrated therapeutic strategies for oncological patients. This review summarizes recent findings linking P2X receptors and ATP to cancer growth, progression and related pain. Special attention has been paid to the role of P2X2, P2X3, P2X4 and P2X7 in the genesis of cancer pain and to the function of P2X7 in tumor growth and metastasis. Therapeutic implications of the administration of different P2X receptor blockers to alleviate cancer-associated pain sensations contemporarily reducing tumor progression are also discussed.     

Increased IL-17-producing CD4(+) T cells in patients with esophageal cancer

Increased interleukin-17 (IL-17)-producing Th (Th17) cells have been described in a variety of human carcinoma cases, however, the mechanism of Th17 cells' accumulation in a tumor microenvironment remains elusive. This study was designed to investigate whether Th17 cells were involved in the development of esophageal cancer. We found that the proportion of Th17 cells increased within the peripheral blood and tumor tissues of esophageal cancer patients. Furthermore, the proportion of circulating Th17 cells was higher in advanced esophageal cancer patients than that in early esophageal cancer patients. In addition, the Th17 cells differentiation-related cytokines (IL-23, IL-1β, and IL-6) and accumulation-related chemokines (CCL22 and CCL20) were present in a tumor microenvironment. Therefore, the findings may partly explain the cause for the increased proportion of Th17 cells and indicate a potential prognostic marker of Th17 cells in esophageal cancer.     

The expression and role of CXC chemokines in colorectal cancer

Cancer is a life-threatening disease world-wide and colorectal cancer is the second common cause of cancer mortality. The interaction between tumor cells and stromal cells plays a crucial role in tumor initiation and progression and is partially mediated by chemokines. Chemokines predominantly participate in the chemoattraction of leukocytes to inflammatory sites. Nowadays, it is clear that CXC chemokines and their receptors (CXCR) may also modulate tumor behavior by several important mechanisms: regulation of angiogenesis, activation of a tumor-specific immune response by attracting leukocytes, stimulation of tumor cell proliferation and metastasis. Here, we review the expression and complex roles of CXC chemokines (CXCL1 to CXCL16) and their receptors (CXCR1 to CXCR6) in colorectal cancer. Overall, increased expression levels of CXC chemokines correlate with poor prognosis.     

BM micrometastases and circulating tumor cells in breast cancer patients: where have we been, where are we now and where does the future lie?

Over the past 15 years early tumor cell dissemination has been detected in patients with breast cancer using sensitive immunocytochemical and molecular assays based on the use of MAb and PCR, respectively. Clinical studies involving more than 4,000 breast cancer patients have now demonstrated that the presence of disseminated tumor cells in BM identified with immuncytochemical assays at primary diagnosis is a strong and independent prognostic factor. The published studies for the detection of disseminated tumor cells in BM fulfill the highest level of evidence as prognostic markers in primary breast cancer. In addition, various assays for the detection of circulating tumor cells in the peripheral blood have been developed recently and some studies suggest a potential clinical relevance of this parameter as a prognostic and predictive factor. Comparative analyzes indicate that the prognostic information derived from BM and blood screening seems to be complementary and not redundant. Advanced methods for molecular characterization of single tumor cells and the surrounding environment have been developed lately, and this approach allows new insights into the metastatic cascade and characterization of targets for therapeutic approaches. Taken together, these findings provide the basis for the implementation of disseminated tumor cells in BM or blood as markers for stratification and assessment of therapies in prospective clinical trials. The valuable information derived from these trials should help to improve future treatment of breast cancer patients.     

Spatial regulation of tumor cell protrusions by RhoC

Systemic metastasis is the dissemination of cancer cells from the primary tumor to distant organs and is the primary cause of death in cancer patients. How do cancer cells leave the primary tumor mass? The ability of the tumor cells to form different types of actin-rich protrusions including invasive protrusions (invadopodia) and locomotory protrusions (lamellipodia [2D] or pseudopodia [3D]), facilitate the invasion and dissemination of the tumor cells. Rho-family of p21 small GTPases plays a direct role in regulating the actin dynamics in these intracellular compartments. Recent studies have shown that the signaling molecules including RhoC/p190RhoGEF/p190RhoGAP acts as a “molecular compass” in order to direct the spatial and temporal dynamics of the formation of these invasive and locomotory protrusions leading to efficient invasion.     

Concomitant expression of the chemokines RANTES and MCP-1 in human breast cancer: a basis for tumor-promoting interactions

The chemokines RANTES (CCL5) and MCP-1 (CCL2) were suggested to contribute, independently, to breast malignancy. In the present study, we asked if the two chemokines are jointly expressed in clinical samples of breast cancer patients, and do they interact in breast tumor cells. We found that RANTES and MCP-1 were expressed by breast tumor cells in primary tumors of Ductal Carcinoma In Situ and of Invasive Ductal Carcinoma, but minimally in normal breast epithelial duct cells. The chemokines were also detected in metastases and pleural effusions. Novel findings showed that co-expression of RANTES and MCP-1 in the same tumor was associated with more advanced stages of disease, suggesting that breast tumors "benefit" from interactions between the two chemokines. Accordingly, MCP-1 significantly promoted the release of RANTES from endogenous pre-made vesicles, in an active process that depended on calcium from intracellular and extracellular sources, and on intracellular transport of RANTES towards exocytosis. Our findings show a chemokine-triggered release of stored pro-malignancy chemokine from breast tumor cells. These observations support a major tumor-promoting role for co-expression of the chemokines in breast malignancy, and agree with the significant association of joint RANTES and MCP-1 expression with advanced stages of breast cancer.