BackgroundProstate cancer (PCa) is a leading cause of cancer-related death in males worldwide. Exacerbated inflammation and angiogenesis have been largely demonstrated to contribute to PCa progression. Diverse naturally occurring compounds and dietary supplements are endowed with anti-oxidant, anti-inflammatory and anti-angiogenic activities, representing valid compounds to target the aberrant cytokine/chemokine production governing PCa progression and angiogenesis, in a chemopreventive setting. Using mass spectrometry analysis on serum samples of prostate cancer patients, we have previously found higher levels of carnitines in non-cancer individuals, suggesting a protective role. Here we investigated the ability of Acetyl-L-carnitine (ALCAR) to interfere with key functional properties of prostate cancer progression and angiogenesis in vitro and in vivo and identified target molecules modulated by ALCAR.MethodsThe chemopreventive/angiopreventive activities ALCAR were investigated in vitro on four different prostate cancer (PCa) cell lines (PC-3, DU-145, LNCaP, 22Rv1) and a benign prostatic hyperplasia (BPH) cell line. The effects of ALCAR on the induction of apoptosis and cell cycle arrest were investigated by flow cytometry (FC). Functional analysis of cell adhesion, migration and invasion (Boyden chambers) were performed. ALCAR modulation of surface antigen receptor (chemokines) and intracellular cytokine production was assessed by FC. The release of pro-angiogenic factors was detected by a multiplex immunoassay. The effects of ALCAR on PCa cell growth in vivo was investigated using tumour xenografts.ResultsWe found that ALCAR reduces cell proliferation, induces apoptosis, hinders the production of pro inflammatory cytokines (TNF-α and IFN-γ) and of chemokines CCL2, CXCL12 and receptor CXCR4 involved in the chemotactic axis and impairs the adhesion, migration and invasion capabilities of PCa and BPH cells in vitro. ALCAR exerts angiopreventive activities on PCa by reducing production/release of pro angiogenic factors (VEGF, CXCL8, CCL2, angiogenin) and metalloprotease MMP-9. Exposure of endothelial cells to conditioned media from PCa cells, pre-treated with ALCAR, inhibited the expression of CXCR4, CXCR1, CXCR2 and CCR2 compared to those from untreated cells. Oral administration (drinking water) of ALCAR to mice xenografted with two different PCa cell lines, resulted in reduced tumour cell growth in vivo.ConclusionsOur results highlight the capability of ALCAR to down-modulate growth, adhesion, migration and invasion of prostate cancer cells, by reducing the production of several crucial chemokines, cytokines and MMP9. ALCAR is a widely diffused dietary supplements and our findings provide a rational for studying ALCAR as a possible molecule for chemoprevention approaches in subjects at high risk to develop prostate cancer. We propose ALCAR as a new possible “repurposed agent’ for cancer prevention and interception, similar to aspirin, metformin or beta-blockers.

Angiogenesis has been shown to play a crucial role in prostate cancer (PCa) progression in several preclinical models, in the clinic, pro-angiogenic factors have been shown to correlate with, Gleason score, metastasis and prognosis in PCa. Plasma levels of VEGF were shown to be higher in patients with metastatic PCa than those with localized disease. The natural killer (NK) cells have been found to be non cytolytic, immunosuppressed in solid cancers. Our group and others demonstrated that tumor infiltrating NK cells in lung and colorectal cancer acquire a pro-angiogenic phenotype. These cells are similar to NK cell within the decidua (dNK), and functionally support angiogenesis in a TGFb and Stat3-dependent manner. A similar subset is present in the peripheral blood of oncology patients. We characterized systemic peripheral blood NK cells (pNK) from PCa patients and their interaction with endothelial cells and macrophages. NK cell subset distribution was investigated by multicolor flow cytometry (FC) for surface antigens on peripheral blood samples PCa patients. Conditioned media (CM) of three different PCa cell lines were used to polarize the healthy donors pNK cells. CM from FACS-sorted PCa pNKs were used for functional studies of angiogenesis, on human umbilical-vein endothelial cells (HUVEC), studies for macrophage recruitment (migration assay on Boyden chambers) and polarization. Molecular studies were performed by real time PCR (qPCR) on HUCECs and macrophages exposed to CM of pNKs. Protein arrays were performed to characterize the secretome on FACS-sorted pNKs. We found that PCa pNKs acquire a pro-angiogenic/decidual-like CD56brightCD9+CD49a+CXCR4+ phenotype. The same phenotype was observed from healthy donors pNK cells exposed to CMs of three different PCa cell lines. These results were confirmed also exposing heathy-donor derived NK cells to conditioned media of 3 different prostate cancer cell lines (PC-3, DU-145, LNCaP), together with increased production of CXCL8, Angiogenin, Angiopoietin1 and reduced production of TNFa, IFNg and GranzymeA. CMs from pNK cells support the formation on capillary-like structures on HUVEC, together with increased expression of VEGF, VEGR-2, CXCL8, ICAM-1 and VCAM-1. Although in male patients, PCa NK cells resemble decidual-like ones. Finding these cells polarized in PB suggests that they could be used as non-invasive marker of inflammation in prostate cancer. Secretome analysis revealed the ability of pNK cells release pro-angiogenic factors (CLXL8, MMP-1, MMP-9; uPAR) and cytokines/chemokines involved in macrophage recruitment (CCL1, CCL2, CCL5, CCL7,CCL13, CXCL1, CXCL11) and M2-like polarization (IL-10). CMs from pNK can recruiting THP-1 monocyte and polarize THP-1 macrophage towards CD206, Arginase1, CXCL8-expressing M2-like/TAM phenotype. Our results place PCa pNK cells interaction with endothelial cells and via macrophage polarization able in supporting angiogenesis in PCa patients. Citation Format: Adriana Albini, Denisa Baci, Matteo Gallazzi, Federico Dehò, Angelo Naselli, Andrea Guernieri, Lorenzo Mortara, Douglas M. Noonan, Antonino Bruno. NK cells from prostate cancer patients acquire a pro-angiogenic phenotype and polarize macrophages towards a M2-like/TAM subset [abstract]. In: Proceedings of the AACR Virtual Special Conference on the Evolving Tumor Microenvironment in Cancer Progression: Mechanisms and Emerging Therapeutic Opportunities; in association with the Tumor Microenvironment (TME) Working Group; 2021 Jan 11-12. Philadelphia (PA): AACR; Cancer Res 2021;81(5 Suppl):Abstract nr LT006.

Epidemiological studies showed that diet can play a relevant role in reducing the risk of developing colon cancer (CC) and lower rate of CC insurgence has been observed amongst populations living within the Mediterranean basin. Olive oil, a major component of the Mediterranean diet, is an abundant source of phenolic compounds. Olive oil production is associated with the generation of waste material, termed ‘olive mill wastewaters’ (OMWW), that have been reported to be enriched in polyphenols as well. Given the beneficial activity of polyphenols on human health, we investigated whether the use of different batches of purified extracts from OMWW, termed A009, might be effective in exerting chemopreventive activities in vitro and in vivo, on CC cell lines. Cell proliferation and survival were evaluated on A009 treated cells by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay, while the induction of apoptosis was assessed by flow cytometry. Further, functional studies to investigate the ability of A009 to interfere with CC cell line adhesion, migration, sprouting and invasion were performed. Finally, the ability of A009 to interfere with CT-26 CRC tumour cell growth was assessed in vivo. Purified hydroxytyrosol, the major component in the A009 extracts, was used as a control. A009 inhibited cell proliferation, migration, invasion, adhesion and sprouting of CC cells along with the release of pro-angiogenic and pro- inflammatory cytokines (VEGF, IL-8) similar to hydroxytyrosol alone. In vivo, A009 inhibited CT-26 tumour growth in a significant manner over that of hydroxytyrosol alone. Our results show that A009 extracts exert promising chemopreventive properties, suggesting that different polyphenols act synergistically, improving their single component effects in CC cell lines. Finally, our results support the idea of repositioning a waste derived material for nutraceutical employment, with environmental and industrial cost management benefits. Citation Format: Barbara Bassani, Teresa Rossi, Daniela De Stefano, Daniele Pizzichini, Paola Corradino, Antonino Bruno, Douglas M. Noonan, Adriana Albini. Chemopreventive activities of a polyphenol rich purified extract from olive oil processing on colon cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 5272. doi:10.1158/1538-7445.AM2017-5272

e17544 Background: Prostate cancer (PCa) represents the second most common cancer worldwide in men. Angiogenesis has been shown to play a crucial role in PCa progression in several preclinical models. Production of pro-angiogenic factors can correlate with metastasis, Gleason score and prognosis in PCa and plasma levels of VEGF were shown to be higher in patients with metastatic PCa than those with localized disease. Natural killer (NK) cells, effector lymphocytes of the innate immunity, have been found to be immunosuppressed in solid cancers, including PCa. Methods: Here, we phenotypically and functionally characterize circulating NK cells from PCa patients and their interaction with endothelial cells and macrophages. NK cell subset distribution has been investigated by multicolor flow cytometry (FACS) for surface antigens on peripheral blood samples PCa patients (TANKs). Conditioned media (CM) from FACS-sorted TANKs were used for functional studies of angiogenesis, on human umbilical-vein endothelial cells (HUVEC), studies for macrophage recruitment (migration assay on Boyden chambers) and polarization. Molecular studies were performed by real time PCR (qPCR) on HUCECs and macrophages exposed to CM of TANKs. Protein arrays were performed to characterize the secretome on FACS-sorted TANKs. Results: We found that TANKs acquire a pro-angiogenic/ dNK-like CD56brightCD9+CD49a+CXCR4+ phenotype. The same phenotype was observed on cytolytic NK cells, from healthy donors, exposed to CMs of three different PCa cell lines (PC-3, DU-145, LNCaP), together with increased production of CXCL8, Angiogenin, Angiopoietin1 and reduced production of TNFa, IFNg and GranzymeA. CMs from TANKs support the formation on capillary-like structures on HUVEC, together with increased expression of VEGF, VEGR-2, CXCL8, ICAM-1 and VCAM-1. Secretome analysis revealed the ability of TANKs release pro-angiogenic pro-invasive factors (CLXL8, MMP-1, MMP-9; uPAR) and cytokines/chemokines involved in macrophage recruitment (CCL1, CCL2, CCL5, CCL7, CCL13, CXCL1, CXCL11) and M2-like polarization (IL-10). Finally, CMs from TANKs can recruit THP-1 monocyte and polarize THP-1 macrophage towards CD206, Arginase1, CXCL8-expressing M2-like/TAM phenotype. Conclusions: Our results place PCa TANKs as effector cells able in supporting angiogenesis in PCa by directly interaction with endothelial cells and via macrophage polarization.

Tissue inhibitors of metalloproteases (TIMPs) have been reported to exert dual roles in cancer, based on the different cancer type and interactions with the tumor microenvironments. As inhibitors of Matrix metalloproteases (MMP) they downregulate invasion, metastasis and angiogenesis. However, TIMP1 levels have been found increased in patients with different types of cancer. Natural Killer cells have been found to be phenotypically and functionally compromised in several solid and hematological cancers. We were the first in characterizing NK pro-angiogenic phenotype in the peripheral blood and tumor tissues of patients with Non-small Cell Lung cancer (NSCLC), colorectal cancers (CRC) and in pleural effusion (PE) of patients with metastatic cancers. Also, we found that pro-angiogenic NK cells in the peripheral blood of colorectal cancer patients release of TIMP-1 and TIMP-2, in a STAT3/STAT5-independent manner. Here, we investigated the effects of TIMP-1 and TIMP-2 recombinant proteins, using a TGFβ-mediated NK cell polarization model, in vitro. The effects of TGFβ, alone or in combination with TIMP-1 or TIMP-2 peptides, was determined by multicolor flow cytometry for surface antigens and cytokine productions, on cytolytic NK cells isolated from healthy subjects. Commercially available antibody membrane arrays was used to determine the modulation of the secretome, on FACS-sorted NK cells, from healthy subjects, following 72 hours of exposure to TGFβ, alone or in combination with TIMP-1 or TIMP-2 peptide. We found that NK cell from healthy donors, exposed to TGFβ, acquire the CD56brightCD9+CD49a+ decidual-like phenotype, together with decreased levels of the activation marker NKG2D. Administration of TIMP1 or TIMP2 peptides was effective in interfering with TGFβ-induced NK cell polarization towards the CD56brightCD9+CD49a+ decidual-like phenotype and in restoration of the levels of the NKG2D activation marker. We also observed that TGFβ-polarized NK cell, when co-treated with TIMP1 or TIMP2, exhibit a trend toward decreased production of VEGF and increased production of the anti-tumor cytokines IFNγ and TNFα Our results suggest a potential role of TIMPs in contrasting the angiogenic switch in NK cells and suggest a possible use of TIMPs peptides in the re-education of anergic/pro-angiogenic NK cells in cancer patients. Citation Format: Matteo Gallazzi, Antonino Bruno, Douglas M. Noonan, William G. Stetler-Stevenson, Adriana Albini. Targeting the TGFΒ/TIMP-1/2 axes to re-educate pro-inflammatory/pro angiogenic NK cells in cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 3159.