Cytokine expression profile in human pancreatic carcinoma cells and in surgical specimens: implications for survival

Abstract

Cytokine shedding by tumor cells into the local microenvironment modulates host immune response, tumor growth, and metastasis. The study aimed to verify the hypothesis that the immunological microenvironment of pancreatic carcinoma exists in a prevalently immunosuppressive state, influencing survival. We analyzed expression profiles of pro-inflammatory (IL-1beta, IL-2, IL-6, IL-8, IL-12 p40, IL-18 and IFN-gamma) and anti-inflammatory (IL-10, IL-11, IL-13 and TGF-beta isoforms) cytokines. The study was performed both in vitro, in five pancreatic carcinoma cell lines (real time RT-PCR), and in specimens from 65 patients, comparing tumoral versus non-tumoral pancreatic tissues (real time RT-PCR and immunohistochemistry). Furthermore, cytokines were measured in supernatants and sera (from patients and controls) by ELISA. All cell lines expressed IL-8, IL-18, TGF-beta1, TGF-beta2 and TGF-beta3, but not IFN-gamma and IL-2 transcripts. Expression of IL-1beta, IL-6, IL-10, IL-11, IL-13 and IL-12 mRNA was variable. All the above cytokines were detected as soluble proteins in supernatants, except IL-13. Tumor tissues overexpressed IL-1beta, IL-6, IL-8, IL-10, IL-11, IL-12 p40, IL-18, IFN-gamma, TGF-beta1, TGF-beta2 and TGF-beta3 at the mRNA level and IL-1beta, IL-18, TGF-beta2 and TGF-beta3 also at the protein level. Conversely, non-tumor tissues had stronger RNA and protein expression of IL-13. Survival was significantly longer in patients with high IL-1beta and IL-11 and moderate IL-12 expression. Serum IL-8, IL-10, IL-12, IL-18, TGF-beta1 and TGF-beta2 were higher in patients than in controls, as opposed to IL-1beta and IL-13. Patients with low circulating levels of IL-6, IL-18 and TGF-beta2 survived longer. Pancreatic cancer is characterized by peculiar cytokine expression patterns, associated with different survival probabilities.

Tumour‐educated macrophages display a mixed polarisation and enhance pancreatic cancer cell invasion

“…BxPC-3 cells co-cultured with PBMCs displayed significantly higher invasive capabilities than BxPC-3 cells cultured alone, in accordance with the tumour-promoting role of TAMs (P<0.001; Fig. 7a-b Previous studies on pancreatic cancer-related inflammation have shown enhanced leukocyte infiltration in the tumour microenvironment and elevated systemic cytokine levels in patients with pancreatic cancer [26][27][28][29][30] . Macrophages, in particular with an alternatively activated M2-associated phenotype, were among the most common leukocyte subsets infiltrating the tumour area 29, 30 .…”

“…Macrophages, in particular with an alternatively activated M2-associated phenotype, were among the most common leukocyte subsets infiltrating the tumour area 29, 30 . This was further reflected in the systemic cytokine levels, where IL-6, IL-8 and IL-10 were elevated in pancreatic cancer patients [26][27][28] . In addition, a recent in vivo study showed that macrophages infiltrated the pancreatic tumour already at the early pre-invasive stages and remained one of the dominating leukocytes throughout the pathogenesis of the disease 31 .…”

P53, hTERT, WT-1, and VEGFR2 are the most suitable targets for cancer vaccine therapy in HLA-A24 positive pancreatic adenocarcinoma

“…One of the speculated reasons why PBMC from patients with lymphocytopenia could not induce a good immune response in our study is that the release of inhibitory immunological cytokines such as transforming growth factor β or IL-10 from pancreatic adenocarcinoma tissue decreases lymphocyte counts and impairs the function of lymphocytes both systemically and in the microenvironment [44]. It was also reported that lymphocyte counts and CTL responses were prognostic markers in advanced cancer cases receiving peptide vaccine therapy [45,46].…”

Impact of surgery and chemotherapy on cellular immunity in pancreatic carcinoma patients in view of an integration of standard cancer treatment with immunotherapy

“…Pancreatic carcinoma cells have been shown to spontaneously secrete these cytokines in vivo, thus defending themselves against immune attack or down-regulate the host's immune system (17,18). Moreover, systemically elevated serum levels of the potentially immunosupressive cytokines IL-10 and TGF-ß, as well as T and DC subsets favouring tolerizing conditions, have also been reported in pancreatic carcinoma patients (19,20).…”