Activation of neuroimmune pathways increases therapeutic effects of radiotherapy on poorly differentiated breast carcinoma.

Recent studies document the importance of neuronal dysfunction in cancer development and metastasis. We reported previously that both depletion of neuropeptides in capsaicin-sensitive sensory nerve endings and vagotomy increases metastasis of triple negative breast carcinoma. Of the sensory neuropeptides, Substance P (SP) is distributed widely for regulation of immune functions. We therefore examined the affects of continuous exposure to low doses of SP on brain metastatic cells of the mouse breast carcinoma (4TBM) in the presence of radiotherapy (RT) thought to increase antigenicity of cancer cells. 4TBM cells have a cancer stem cell phenotype and induce extensive visceral metastasis after orthotopic inoculation into the mammary pad. Results demonstrated that SP treatment decreases the number of tumor-infiltrating myeloid-derived suppressor cells as well as the TNF-α response to LPS challenge. SP also increased CD4+Cd25(bright) cells in draining lymph nodes of tumor-bearing animals and IFN-γ secretion from leukocyte culture prepared from lymph nodes and spleens of tumor-bearing animals. SP also prevented tumor-induced degeneration of sensory nerve endings and altered release of angiogenic factors from cancer-associated fibroblasts (CAF) and tumor explants. In accordance with these observed immunological effects, combination treatment of continuous SP with a single dose of RT induced complete tumor regression and significantly reduced or prevented metastasis in 50% of the animals while suppressing primary tumor growth and metastasis in the remaining mice. These original findings demonstrate that SP through neuroimmune modulation can prevent formation of immune suppression in the tumor microenvironment, enhance cytotoxic immunity in the presence of RT and prevent metastatic growth.

Differential characteristics of heart, liver, and brain metastatic subsets of murine breast carcinoma.

Breast carcinoma is comprised of heterogeneous groups of cells with different metastatic potential. To develop effective therapeutic strategies targeting metastatic disease, it is crucial to understand the characteristics of breast cancer cells that enable metastasis to distant organs. 4THM breast carcinoma cells are the cells of 4T1 primary tumors that metastasized to the heart. Cells of 4THM tumors which metastasized to liver (4TLM) were previously isolated. Recently macroscopic brain metastasis in 4THM injected animals, were isolated to obtain a brain metastatic cell line (4TBM). Using an orthotopic mouse model differential characteristic of cells metastasized to heart (4THM), liver (4TLM), and brain (4TBM) were compared for ability to metastasize and expression of stem cell markers. We found that 4TLM cells produced significantly more lung and liver metastasis compared to 4TBM and 4THM cells. In vitro, proliferation as well as migration rate of 4TLM cells was also significantly higher than the other cell lines. Remarkably primary tumors formed by 4TLM cells expressed significant amounts of CD34, a marker for mesenchymal malignancies. Markers of epithelial-mesenchymal transition were expressed in all metastatic cells, but the degree of expression differed. Majorities of 4TLM, 4THM, and 4TBM cells were CD44+ CD24- whereas, 12 % of 4TLM cells also expressed membranous CD24. Conditioned mediums of non-metastatic 67NR breast tumors and cancer-associated fibroblasts inhibited growth of highly metastatic 4TLM cells. Malignant cells metastasized to brain were distinguished by membranous E-cadherin expression that was markedly higher in 4TBM cells grown as spheroids suggesting E-cadherin is required for brain metastasis. Differential features of heart, brain, and liver metastatic cells in a syngenic model was shown in this study for the first time. These findings not only provide a model to explore new treatment modalities, but also demonstrate differential features of cancer cells that originally homed to a certain organ, such as liver or brain.

Olvanil activates sensory nerve fibers, increases T cell response and decreases metastasis of breast carcinoma.

BACKGROUND: Inactivation of sensory neurons expressing transient receptor potential vanilloid 1 (TRPV1) enhances breast cancer metastasis. Sensory neurons have profound effects on immune response to a wide range of diseases including cancer. Hence, activation of sensory nerves using feasible approaches such as specific TRPV1 agonists may inhibit breast cancer metastasis through neuroimmune pathways. TRPV1 agonists are considered for the treatment of pain and inflammatory diseases. METHODS: We here first determined the effects of four different TRPV1 agonists on proliferation of three different metastatic breast carcinoma cells since TRPV1 is also expressed in cancer cells. Based on the results obtained under in-vitro conditions, brain metastatic breast carcinoma cells (4TBM) implanted orthotopically into the mammary-pad of Balb-c mice followed by olvanil treatment (i.p.). Changes in tumor growth, metastasis and immune response to cancer cells were determined. RESULTS: Olvanil dose-dependently activated sensory nerve fibers and markedly suppressed lung and liver metastasis without altering the growth of primary tumors. Olvanil (5 mg/kg) systemically increased T cell count, enhanced intra-tumoral recruitment of CD8+ T cells and increased IFN-γ response to irradiated cancer cells and Con-A. Anti-inflammatory changes such as increased IL-10 and decrease IL-6 as well as S100A8+ cells were observed following olvanil treatment. CONCLUSIONS: Our results show that anti-metastatic effects of olvanil is mainly due to activation of neuro-immune pathways since olvanil dose used here is not high enough to directly activate immune cells. Furthermore, olvanil effectively depletes sensory neuropeptides; hence, olvanil is a good non-pungent alternative to capsaicin.

Zoledronic acid concurrent with either high- or reduced-dose palliative radiotherapy in the management of the breast cancer patients with bone metastases: a phase IV randomized clinical study.

INTRODUCTION: In this prospective study, the efficacy and safety of radiotherapy combined with zoledronic acid was evaluated. MATERIALS AND METHODS: Breast cancer patients with painful bone metastases were randomized to either high- or reduced-dose radiotherapy. All patients received zoledronic acid (4 mg) every 28 days from the beginning of radiotherapy. Analgesic and pain scores in addition to visual analog score (VAS) for treatment satisfaction and whole-body bone scintigraphy were evaluated. RESULTS AND CONCLUSION: No significant differences could be found in analgesic or pain scores and bone scintigraphy results between the groups. Our results suggest that reduced-dose radiotherapy produces similar response rates and response durations when used concomitantly with zoledronic acid.

HSP90 inhibitor PU-H71 increases radiosensitivity of breast cancer cells metastasized to visceral organs and alters the levels of inflammatory mediators.

Heat shock protein 90 (HSP90) inhibitors are considered as new radiosensitizing agents. PU-H71, a novel HSP90 inhibitor, is under evaluation for the treatment of advanced cancer. It is however not known whether PU-H71 alters radiosensitivity of metastatic breast cancer. Hence, we here evaluated mechanisms of possible anti-tumoral and radiosensitizing effects of PU-H71 on breast carcinoma cells metastasized to vital organs such as the liver and brain. The effect of PU-H71 on proliferation of breast carcinoma cells was determined using 4T1 cells and its brain (4TBM), liver (4TLM), and heart (4THM) metastatic subsets as well as non-metastatic 67NR cells. Changes in radiation sensitivity were determined by clonogenic assays. Changes in client proteins and levels of angiogenic and inflammatory mediators from these cancer cell cultures and ex vivo cultures were detected. PU-H71 alone inhibited ERK1/2, p38, and Akt activation and reduced N-cadherin and HER2 which further documented the anti-tumoral effects of PU-H71. The combination of PU-H71 and radiotherapy induced cytotoxic effect than PU-H71 alone, and PU-H71 showed a radiosensitizing effect in vitro. On the other hand, PU-H71 and radiation co-treatment increased p38 phosphorylation which is one of the hallmarks of inflammatory response. Accordingly, IL-6 secretion was increased following PU-H71 and radiotherapy co-treatment ex vivo. Levels of angiogenic and inflammatory factors such as MIP-2, SDF-1, and VEGF were increased under in vitro conditions but not under ex vivo conditions. These results demonstrated for the first time that PU-H71 enhances therapeutic effects of radiotherapy especially in highly metastatic breast carcinoma but a possible increase in inflammatory response should also be considered.

TRAIL death receptor-4 expression positively correlates with the tumor grade in breast cancer patients with invasive ductal carcinoma.

PURPOSE: Tumor necrosis factor-related apoptosis inducing ligand (TRAIL) selectively induces apoptosis in cancer cells but not in normal cells, and a number of clinical trials have recently been initiated to test the safety and antitumoral potential of TRAIL in cancer patients. Four different receptors have been identified to interact with TRAIL: two are death-inducing receptors (TRAIL-R1 [DR4] and TRAIL-R2 [DR5]), whereas the other two (TRAIL-R3 [DcR1] and TRAIL-R4 [DcR2]) do not induce death upon ligation and are believed to counteract TRAIL-induced cytotoxicity. Because high levels of DcR2 expression have recently been correlated with carcinogenesis in the prostate and lung, this study investigated the importance of TRAIL and TRAIL receptor expression in breast cancer patients with invasive ductal carcinoma, taking various prognostic markers into consideration. METHODS AND MATERIALS: Immunohistochemical analyses were performed on 90 breast cancer patients with invasive ductal carcinoma using TRAIL and TRAIL receptor-specific antibodies. Age, menopausal status, tumor size, lymph node status, tumor grade, lymphovascular invasion, perineural invasion, extracapsular tumor extension, presence of an extensive intraductal component, multicentricity, estrogen and progesterone receptor status, and CerbB2 expression levels were analyzed with respect to TRAIL/TRAIL receptor expression patterns. RESULTS: The highest TRAIL receptor expressed in patients with invasive ductal carcinoma was DR4. Although progesterone receptor-positive patients exhibited lower DR5 expression, CerbB2-positive tissues displayed higher levels of both DR5 and TRAIL expressions. CONCLUSIONS: DR4 expression positively correlates with the tumor grade in breast cancer patients with invasive ductal carcinoma.

Prognostic role of Ebstein-Barr virus latent membrane protein-1 and interleukin-10 expression in patients with nasopharyngeal carcinoma.

PURPOSE: We aimed to investigate Ebstein-Barr virus (EBV) latent membrane protein-1 (LMP-1) and Interleukine-10 (IL-10) expression in nasopharyngeal carcinoma (NPC) patients and to evaluate their prognostic significance. MATERIAL AND METHODS: Between 1993 and 1999, 166 patients were treated with the diagnosis of nonmetastatic NPC at our department. The expression of LMP-1 and IL-10 was investigated by using an immunohistochemical approach in 74 (53 male, 21 female) patients whose paraffin embedded tissue samples were available. A detailed histopathological analysis including degree of apoptosis and lymphocyte infiltration was made and all patients were reclassified according to the World Health Organization (WHO) classification. Univariate, multivariate, and logistic regression analyses were performed using all clinical and pathological prognostic factors. All patients were treated with radiotherapy +/- chemotherapy. Follow-up ranged between 12 and 80 months (median: 32). RESULTS: The histopathological diagnosis was WHO-I in 1 (1.3%), WHO-II in 15 (20.2%), and WHO-III in 58 (79.5%) patients. There were 38 (51%) patients with IL-10 expression and 44 (61%) patients with LMP-1 expression. Twenty-seven (36.4%) patients were found to be both IL-10 and LMP-1 positive. There were significantly more N0 disease in patients without LMP-1 expression compared to LMP-1 positive patients (65% vs. 35%, p = 0.01). The logistic regression analysis showed advanced nodal involvement to be the major parameter affecting the expression of IL-10 (p = 0.03). Three-year overall survival (OS), locoregional relapse free survival (LRRFS), and distant metastasis free survival (DMFS) rates were 67.8%, 84.4%, and 74.3%, respectively, for the whole group. On univariate analysis, LRRFS was significantly lower in WHO-III patients, DMFS was significantly lower in advanced nodal disease and IL-10 negative patients, and OS was significantly lower in WHO-III patients. Multivariate analysis showed that WHO-III and T2 patients were significantly associated with lower OS and N3 patients were significantly associated with lower DMFS. CONCLUSION: We observed a high rate (61%) of EBV (LMP-1 positive) and NPC association in our patients. LMP-1 positive tumors were found to be more prone to invade lymph nodes. Patients with negative IL-10 expression had more advanced N disease. We did not find a prognostic significant role of IL-10 and EBV LMP-1 on survival in multivariate analysis.