Dynamic alteration of soluble serum biomarkers in healthy aging.

Dysbalanced production of inflammatory cytokines is involved in immunosenescence in aging. The age-related changes of the levels of circulating inflammatory mediators and their clinical importance have not been investigated until recently. Still, little is known about the influence of aging on circulating levels of many cytokines, chemokines, growth factors, and angiogenic factors. In the present study, we evaluated the effect of aging on 30 different serum biomarkers involved in pro- and anti-inflammatory responses using multianalyte LabMAP Luminex technology. The simultaneous measurement of serological markers has been done in 397 healthy subjects between 40 and 80 years old. We demonstrated an increase in serum interferon-gamma-inducible chemokines (MIG and IP-10), eotaxin, chemoattractant for eosinophils, and soluble TNFR-II with advancing age. Serum levels of EGFR and EGF, important regulators of cell growth and differentiation, were decreased with age in healthy donors. These data suggest novel pathways, which may be involved in age-associated immunosenescence.

Multiplex analysis of serum cytokines in melanoma patients treated with interferon-alpha2b.

PURPOSE: Interferon (IFN)-alpha2b is the only Food and Drug Administration-approved treatment for operable high-risk melanoma that has been shown to significantly and durably prolong relapse-free survival (RFS) of patients with stage IIB-III melanoma. Development of reliable serum assays may contribute to the development of methods for earlier detection of melanoma and the selection of patients who may be most susceptible to current available interventions with IFNalpha. EXPERIMENTAL DESIGN: A powerful high-throughput xMAP multiplex immunobead assay technology (Luminex Corp., Austin, TX) was used to simultaneously test 29 cytokines, chemokines, angiogenic as well as growth factors, and soluble receptors in the sera of 179 patients with high-risk melanoma and 378 healthy individuals. RESULTS: Serum concentrations of interleukin (IL)-1alpha, IL-1beta, IL-6, IL-8, IL-12p40, IL-13, granulocyte colony-stimulating factor, monocyte chemoattractant protein 1 (MCP-1), macrophage inflammatory protein (MIP)-1alpha, MIP-1beta, IFNalpha, tumor necrosis factor (TNF)-alpha, epidermal growth factor, vascular endothelial growth factor (VEGF), and TNF receptor II were found to be significantly higher in patients with resected high-risk melanoma compared with healthy controls. Bayesian Network algorithm classification of the data offered 90% sensitivity at 98% specificity with 96.5% of melanoma patients distinguished from healthy individuals. IFN-alpha2b therapy resulted in a significant decrease of serum levels of immunosuppressive and tumor angiogenic/growth stimulatory factors (VEGF, epidermal growth factor, and hepatocyte growth factor) and increased levels of antiangiogenic IFN-gamma inducible protein 10 (IP-10) and IFN-alpha. Pretreatment levels of proinflammatory cytokines IL-1beta, IL-1alpha, IL-6, TNF-alpha, and chemokines MIP-1alpha and MIP-1beta were found to be significantly higher in the serum of patients with longer RFS values of 1 to 5 and >5 years when compared with patients with shorter RFS of <1 year. CONCLUSION: These data show that multiplexed analysis of serum biomarkers is useful for the evaluation of prognostic markers of clinical outcome and potential predictive markers of response to IFN-alpha2b in patients with high-risk operable melanoma.

Multiple biomarker panels for early detection of ovarian cancer.

Ovarian cancer is the eighth most common cause of cancer mortality in women. It is diagnosed in more than 20,000 women in the USA each year and approximately 15,000 women die of the disease annually. The majority of patients are diagnosed with advanced-stage ovarian cancer, as this deadly disease causes minimal and nonspecific symptoms until late in the course of the disease. No standardized screening test exists to reliably detect ovarian cancer. Cancer antigen (CA)-125 is a protein antigen found at abnormally high levels in the blood of many women with ovarian cancer. Most healthy women have CA-125 levels of below 35 units/microl of blood serum. However, a number of noncancerous conditions can cause elevated CA 125 levels, and many women with early-stage ovarian cancer have normal CA-125 levels. Owing to these limitations, this test is not recommended for routine screening in women who are not at high risk or who do not have specific symptoms of the disease. Currently, many researchers are focusing on simultaneous examination of multiple markers to increase sensitivity of the screening test for early detection of ovarian cancer. Analysis of the current literature shows that combining several biomarkers dramatically improves sensitivity of CA-125 in ovarian cancer patients. This article provides a comprehensive overview of existing studies in the area of multimarker panel development for the early detection and monitoring of ovarian cancer. Our literature review demonstrates that a multimarker approach for the generation of a prototype assay for early detection of ovarian cancer has a great potential to lead to the development of a screening test for this disease.

Intratumoral cytokines/chemokines/growth factors and tumor infiltrating dendritic cells: friends or enemies?

The tumor microenvironment consists of a variable combination of tumor cells, stromal fibroblasts, endothelial cells and infiltrating leukocytes, such as macrophages, T lymphocytes, and dendritic cells. A variety of cytokines, chemokines and growth factors are produced in the local tumor environment by different cells accounting for a complex cell interaction and regulation of differentiation, activation, function and survival of multiple cell types. The interaction between cytokines, chemokines, growth factors and their receptors forms a comprehensive network at the tumor site, which is primary responsible for overall tumor progression and spreading or induction of antitumor immune responses and tumor rejection. Although the general thought is that dendritic cells are among the first cells migrating to the tumor site and recognizing tumor cells for the induction of specific antitumor immunity, the clinical relevance of dendritic cells at the site of the tumor remains a matter of debate regarding their role in the generation of successful antitumor immune responses in human cancers. While several lines of evidence suggest that intratumoral dendritic cells play an important role in antitumor immune responses, understanding the mechanisms of dendritic cell/tumor cell interaction and modulation of activity and function of different dendritic cell subtypes at the tumor site is incomplete. This review is limited to discussing the role of intratumoral cytokine network in the understanding immunobiology of tumor-associated dendritic cells, which seems to possess different regulatory functions at the tumor site.

Comparative analysis of antitumor activity of CD40L, RANKL, and 4-1BBL in vivo following intratumoral administration of viral vectors or transduced dendritic cells.

The tumor necrosis factor (TNF) family comprises a group of ligands that regulate cell proliferation, differentiation, activation, maturation and apoptosis through interaction with the corresponding TNF receptor family members. In this study, we have evaluated whether adenovirus-mediated intratumoral gene transfer of CD40L, RANKL, or 4-1BBL elicits an immune response to established murine MC38 and TS/A tumors. Intratumoral administration of the recombinant adenoviral vectors expressing CD40L, RANKL or 4-1BBL 7 days post-tumor cell inoculation resulted in significant inhibition of MC38 tumor growth for all three ligands when compared with control groups treated with either saline or control adenovirus. However, intratumoral injection of Ad-4-1BBL or Ad-CD40L resulted in a significantly stronger inhibition of TS/A tumor progression than did Ad-RANKL treatment. We also demonstrated that intratumoral administration of dendritic cells (DC) transduced with adenoviral vectors encoding the TNF-related ligands resulted in a significant inhibition of MC38 tumor growth as compared with control groups treated with Ad-LacZ-transduced DC or saline-treated DC. In addition, DC overexpressing CD40L secreted considerably more IL-12 and expressed higher levels of the co-stimulatory molecules, CD80, CD86 and CD40, than did DC overexpressing LacZ, 4-1BBL or RANKL. We have also demonstrated that DC/CD40L, DC/4-1BBL, and DC/RANKL survived significantly longer than control DC or DC infected with the LacZ vector. Taken together, these results demonstrate that adenoviral gene transfer of CD40L, RANKL or 4-1BBL elicit a significant antitumor effect in two different tumor models, with CD40L gene transfer inducing the strongest antitumor effect.

Increased function and survival of IL-15-transduced human dendritic cells are mediated by up-regulation of IL-15Ralpha and Bcl-2.

It has been recently demonstrated that dendritic cells (DC) coincubated with interleukin (IL)-15 express high levels of the Bcl-2 family of proteins and display an increased resistance to tumor-induced apoptotic death. Here, the phenotype, functions, and survival of human DC transduced with adenoviral vector encoding the human IL-15 gene were studied. The transduction of DC with the IL-15 gene resulted in a significant elevation of expression of CD83, CD86, and CD40 molecules, which was blocked by anti-IL-15 monoclonal antibodies. This effect was also accompanied by an increased production of IL-12 and stimulated ability of DC to induce T cell proliferation. Furthermore, transduction of DC with the IL-15 gene significantly increased their resistance to prostate cancer-induced apoptosis: Overexpression of IL-15 on DC blocked tumor-induced inhibition of Bcl-2 expression and prolonged DC survival after coincubation with tumor cells. Finally, overexpression of IL-15 in DC was associated with a higher level of expression of IL-15 receptor alpha chain mRNA. In summary, these results suggest that transduction of DC with the IL-15 gene markedly stimulates DC function and protects them from tumor-induced apoptosis.

Local administration of IL-12-transfected dendritic cells induces antitumor immune responses to colon adenocarcinoma in the liver in mice.

Colorectal cancer is one of the most common fatal malignancies in the United States, with an incidence second only to lung cancer. The liver is the most common site of colorectal metastases and frequently the only affected organ once the primary tumor has been surgically removed. The only potentially curative treatment for metastatic colorectal cancer in the liver is surgery, although most patients are not eligible for resection. We have therefore, evaluated the therapeutic efficacy of dendritic cells (DCs) engineered to express IL-12 in a liver metastasis model. Direct administration of DCs into the portal vein significantly inhibited the growth of established MC38 colon carcinoma in the liver in C57BL/6 mice. This effect was accompanied by an intratumoral accumulation of CD4+, CD8+, and NLDC-145+ immune effector cells, and also resulted in a systemic immune response as determined by enhanced production of IFN-gamma by T lymphocytes isolated from both spleen and draining lymph nodes. Evaluation of homing of Cy3-labeled DCs following the portal vein injection confirmed their distribution in the liver and lymphoid tissue. Thus, a local delivery of DCs transduced with the IL-12 gene can not only inhibit colorectal tumor growth in vivo but also mount systemic antitumor immune responses. This approach is likely to improve the outcome of immunotherapy for metastatic colorectal cancer since high numbers of tumor-associated DCs positively correlate with a more favorable prognosis. Simultaneous local gene therapy with IL-12 will further improve clinical efficacy without placing the patient at risk for systemic toxicity.

Inhibition of CD40 expression and CD40-mediated dendritic cell function by tumor-derived IL-10.

As CD40 plays a key role in both antitumor immunity and DC maturation, we have studied the regulation of its expression during DC hematopoiesis (dendropoiesis) in vitro and in vivo in the tumor microenvironment. Using MC38 colon adenocarcinoma tumor models, we have demonstrated that DCs generated in vitro from bone marrow precursors obtained from tumor-bearers have significantly lower expression of CD40 molecules compared to DCs generated from tumor-free mice. Furthermore, CD40 expression on DCs isolated from the spleens of tumor-bearing mice was also significantly reduced, suggesting that tumor-derived factors inhibit CD40 expression on DCs during dendropoiesis both in vitro and in vivo. Interestingly, CD40 ligation on DCs generated from tumor-bearers did not result in inducible expression of IL-12 protein or IL-12 p40 mRNA. However, Staphylococcus aureus-induced IL-12 production by DCs was not altered in tumor-bearers, confirming that inhibition of IL-12 production by DCs generated in vitro from tumor-bearing mice was due to reduced expression of CD40 on DCs. We have also shown that MC38 tumor cells produce IL-10 and that exogenous IL-10 causes downregulation of CD40 expression on DCs. In addition, endogenous IL-10 produced by colon carcinoma cells inhibited CD40-dependent IL-12 production by DCs since tumor-induced inhibition of IL-12 production was abrogated by neutralizing anti-IL-10 antibody. Finally, systemic administration of FLT3L and/or CD40L reversed CD40 and IL-12 (p40) deficiency of DCs in tumor-bearing mice in vivo. These findings thus demonstrate that tumor-derived factors, including IL-10, inhibit CD40 expression on DCs and DC precursors and suppress their maturation and function.