Surviving host innate immunity: Cancer cells can turn a deadly assault into an advantage

Sexual dimorphism and the role of estrogen in the immune microenvironment of liver metastases

Liver metastases (LM) remain a major cause of cancer-associated death and a clinical challenge. Here we explore a sexual dimorphism observed in the regulation of the tumor immune microenvironment (TIME) of LM, wherein the accumulation of myeloid-derived suppressor cells (MDSC) and regulatory T cells in colon and lung carcinoma LM is TNFR2-dependent in female, but not in male mice. In ovariectomized mice, a marked reduction is observed in colorectal, lung and pancreatic carcinoma LM that is reversible by estradiol reconstitution. This is associated with reduced liver MDSC accumulation, increased interferon-gamma (IFN-γ) and granzyme B production in CD8+ T cells and reduced TNFR2, IDO2, TDO and Serpin B9 expression levels. Treatment with tamoxifen increases liver cytotoxic T cell accumulation and reduces colon cancer LM. The results identify estrogen as a regulator of a pro-metastatic immune microenvironment in the liver and a potential target in the management of liver metastatic disease.

The clinical significance of serum adipocytokines level in patients with lung cancer

Background

Adipocytokines were known to play a relevant role in metabolism, inflammation responses and carcinogenesis of several malignancies. Our aims were to detect the expression of serum adipocytokines, explore their potential diagnostic ability and relationship with clinicopathological characteristics of lung cancer.

Methods

Adipocytokines, insulin-like growth factor binding protein 1 (IGFBP-1), resistin, tumor necrosis factors (TNFα), TNF RI and TNF RII, vascular endothelial growth factor (VEGF), leptin, interleukin (IL)-6 and IL-10, chemerin, brain-derived neurotrophic factor (BDNF), plasminogen activator inhibitor-1 (PAI-1) were assessed in 49 untreated lung cancer patients and 20 healthy controls. The protein chip was used to detect the serum levels of adipocytokines.

Results

Lung cancer patients exhibited significantly elevated serum IGFBP-1, TNF RI, VEGF, TNF RII, PAI-1 and IL-6 levels compared to controls (P<0.05) and most of these adipocytokines revealed a modest discriminative ability for the diagnosis of lung cancer, while BDNF were lower in patients (P<0.05). TNF RI was associated with distant metastasis of lung cancer, while there was no relation between other adipocytokines and the patient clinicopathological features.

Conclusions

These results suggest that cytokines IGFBP-1, TNF RI, VEGF, TNF RII, PAI-1 and IL-6 may be involved in the development and progression of lung cancer, and TNF RI may be involved in distant metastasis of lung cancer. Additionally, IGFBP-1, TNF RI, VEGF and TNF RII probably represent potentially useful biomarkers for the diagnosis of lung cancer.

The diverse roles of the TNF axis in cancer progression and metastasis

Metastasis is a multi-step process that ultimately depends on the ability of disseminating cancer cells to establish favorable communications with their microenvironment. The tumor microenvironment consists of multiple and continuously changing cellular and molecular components. One of the factors regulating the tumor microenvironment is TNF-α, a pleiotropic cytokine that plays key roles in apoptosis, angiogenesis, inflammation and immunity. TNF-α can have both pro- and anti-tumoral effects and these are transmitted via two major receptors, the 55 kDa TNFR1 and the 75 kDa TNFR2 that have distinct, as well as overlapping functions. TNFR1 is ubiquitously expressed while the expression of TNFR2 is more restricted, mainly to immune cells. While TNFR1 can transmit pro-apoptotic or pro-survival signals through a complex network of downstream mediators, the role of TNFR2 is less well understood. One of its main functions is to act as a survival factor and moderate the pro-apoptotic effects of TNFR1, particularly in immune cells. In this review, we summarize the evidence for the involvement of the TNF system in the progression of the metastatic process from its contribution to the early steps of tumor cell invasion to its role in the colonization of distant sites, particularly the liver. We show how the TNF receptors each contribute to these processes by regulating and shaping the tumor microenvironment. Current evidence and concepts on the potential use of TNF targeting agents for cancer prevention and therapy are discussed.