Potassium increases the antitumor effects of ascorbic acid in breast cancer cell lines in vitro.

Ascorbic acid (A) has been demonstrated to exhibit anti-cancer activity in association with chemotherapeutic agents. Potassium (K) is a regulator of cellular proliferation. In the present study, the biological effects of A and K bicarbonate, alone or in combination (A+K), on breast cancer cell lines were evaluated. The survival of cancer cells was determined by sulforhodamine B cell proliferation assay, while analysis of the cell cycle distribution was conducted via fluorescence-activated cell sorting. In addition, the expression of signaling proteins was analyzed upon treatment. The results indicated that there was a heterogeneous response of the different cell lines to A and K, and the best effects were achieved by A+K and A treatment. The interaction between A+K indicated an additive or synergistic effect. In addition, A+K increased the percentage of cells in the sub-G1 phase of the cell cycle, and was the most effective treatment in activating the degradation of poly(adenosine diphosphate-ribose) polymerase-1. In the breast cancer cell line MCF-7, A+K induced the appearance of the 18 kDa isoform of B-cell lymphoma-2-associated X protein (Bax), which is a more potent inducer of apoptosis than the full-length Bax-p21. The effects of A and K on the phosphorylation of extracellular signal-regulated kinase (ERK)1 and ERK2 were heterogeneous. In addition, treatment with K, A and A+K inhibited the expression of nuclear factor-κB. Overall, the results of the present study indicated that K potentiated the anti-tumoral effects of A in breast cancer cells in vitro.

Resveratrol potentiates the in vitro and in vivo anti-tumoral effects of curcumin in head and neck carcinomas.

The survival rate of head and neck squamous cell carcinomas (HNSCC) patients has not considerably changed over the last two decades. Polyphenols inhibit the growth of cancer cells. We determined whether the combination of Resveratrol (RES) and Curcumin (CUR) enhanced their in vitro and in vivo antitumor activities on HNSCC cell lines compared to the single compounds. We provide evidence that RES potentiated the apoptotic effect and reduced the IC50 of CUR on HNSCC cell lines. The model of compounds interaction indicated the onset of an additive effect of the two compounds compared to the single treatment after decrease of their concentrations. RES+CUR compared to CUR increased the PARP-1 cleavage, the Bax/Bcl-2 ratio, the inhibition of ERK1 and ERK2 phosphorylation, and the expression of LC3 II simultaneously with the formation of autophagic vacuoles. RES and CUR induced cytoplasmic NF-κB accumulation. RES+CUR administrations were safe in BALB/c mice and reduced the growth of transplanted salivary gland cancer cells (SALTO) more efficiently than CUR. Overall, combinations of CUR and RES was more effective in inhibiting in vivo and in vitro cancer growth than the treatment with CUR. Additional studies will be needed to define the therapeutic potential of these compounds in combination.

Intratumoral delivery of recombinant vaccinia virus encoding for ErbB2/Neu inhibits the growth of salivary gland carcinoma cells.

BACKGROUND: The antitumor activity induced by intratumoral vaccination with poxvirus expressing a tumor antigen was shown to be superior to that induced by subcutaneous vaccination. Salivary gland carcinomas overexpress ErbB2. Trastuzumab, a monoclonal antibody to ErbB2, was proposed for salivary gland tumors treatment. We explored the effectiveness of intratumoral vaccination with the recombinant vaccinia virus ErbB2/Neu (rV-neuT) vaccine in hampering the growth of transplanted Neu-overexpressing BALB-neuT salivary gland cancer cells (SALTO) in BALB-neuT mice. METHODS: BALB-neuT male mice were subcutaneously injected with SALTO tumor cells and intratumorally vaccinated twice with different doses of either rV-neuT or V-wt (wild-type). Tumors were measured weekly. The presence of anti-ErbB2/Neu antibodies was assayed by ELISA, immunoprecipitation or indirect immunofluorescence. Biological activity of immune sera was investigated by analyzing antibody-dependent cellular cytotoxicity (ADCC), SALTO cells proliferation and apoptosis, ErbB2/Neu receptor down regulation and ERK1/2 phosphorylation. Anti-Neu T cell immunity was investigated by determining the release of IL-2 and IFN-gamma in T cells supernatant. Survival curves were determined using the Kaplan-Meier method and compared using the log-rank test. Differences in tumor volumes, number of apoptotic cells, titer of the serum, percentage of ADCC were evaluated through a two-tailed Student's t-test. RESULTS: rV-neuT intratumoral vaccination was able to inhibit the growth of SALTO cancer cells in a dose-dependent manner. The anti-Neu serum titer paralleled in vivo antitumor activity of rV-neuT vaccinated mice. rV-neuT immune serum was able to mediate ADCC, inhibition of SALTO cells proliferation, down regulation of the ErbB2/Neu receptor, inhibition of ERK1/2 phosphorylation and induction of apoptosis, thus suggesting potential mechanisms of in vivo tumor growth interference. In addition, spleen T cells of rV-neuT vaccinated mice released IFN-gamma and IL-2 upon in vitro stimulation with several Neu-specific peptides located in the extracellular domain of Neu sequence. CONCLUSIONS: rV-neuT intratumoral vaccination could be employed to induce an efficient antitumor response and reject transplanted salivary gland tumors. Our findings may have important implications for the design of cancer vaccine protocols for the treatment of salivary gland tumors and other accessible tumors using intratumoral injection of recombinant vaccinia virus.

Local radiotherapy increases the level of autoantibodies to ribosomal P0 protein but not to heat shock proteins, extracellular matrix molecules and EGFR/ErbB2 receptors in prostate cancer patients.

Prostate cancer is a common cancer among men in developed countries. Although hormonotherapy and radiotherapy (RT) represent valid therapies for prostate cancer treatment, novel immunological approaches have been explored. The development of clinical trials employing cancer vaccines has indicated that immune response to tumor antigens can be boosted and that vaccine administration can improve patient survival. Immune response to tumor antigens could also be enhanced after standard therapies. In the present study, we determined the occurrence of antibodies to extracellular matrix (ECM) molecules, heat shock protein (HSP), ribosomal P0 protein, EGFR, ErbB2 and prostate-specific antigen (PSA) in 35 prostate cancer patients prior to and following local RT and hormonotherapy. We demonstrated that immunity to P0, ECM molecules [collagens (C) CI, CIII, CV, fibronectin (FN) and laminin (LM)] and to HSP90 was associated with malignancy in untreated patients. None of the patient sera showed antibodies to EGFR, while 2 and 1 patients showed reactivity to ErbB2 and PSA, respectively. We also demonstrated that 8 months after therapy the IgG serum levels to CI, CIII, FN and HSP90 significantly decreased. Conversely, the level of P0 autoantibodies increased after therapy in 10 patients. Five of the 10 patients with increased levels of P0 autoantibodies were treated with RT plus hormonotherapy. Treatment of patients did not change the levels of antibodies against EGFR, ErbB2 and PSA. Our results indicated that the modification of antibody level to self molecules after standard treatment of prostate cancer patients is influenced by the type of antigen. Ribosomal P0 protein appears to be a high immunogenic antigen and its immunogenicity increases following RT. In addition, 10 patients with increased levels of autoantibodies to P0 showed PSA mean levels lower than the remaining 25 patients at 18 months. This study may contribute to a better understanding of the immunobiological behavior of prostate cancer patients following standard treatment.

The effects of dietary flavonoids on the regulation of redox inflammatory networks.

Dietary flavonoids are a large family of polyphenols ubiquitously expressed in plants. Recent evidence show that flavonoids possess several anti-inflammatory activities due to their ability to scavenge reactive oxygen and nitrogen species (ROS and RNS), to inhibit the pro-inflammatory activity of ROS-generating enzymes including cyclooxygenase (COX), lipoxygenase (LOX) and inducible nitric oxide synthase (iNOS) and to modulate different intracellular signaling pathways from NF-kB to mitogen-activated protein kinases (MAPKs) through perturbation of redox-sensible networks in immune cells. This report will review current knowledge on the anti-inflammatory effects of flavonoids on immune cells focusing on their ability to modulate multiple redox-sensible pathways involved in inflammation.

Carcinoembryonic antigen (CEA)-based cancer vaccines: recent patents and antitumor effects from experimental models to clinical trials.

Carcinoembryonic antigen (CEA), a glycosylated protein of MW 180 kDa, is overexpressed in a wide range of human carcinomas, including colorectal, gastric, pancreatic, non-small cell lung and breast carcinomas. Accordingly, CEA is one of several oncofetal antigens that may serve as a target for active anti-cancer specific immunotherapy. Experimental results obtained by employing animal models have supported the design of clinical trials using a CEA-based vaccine for the treatment of different types of human cancers. This review reports findings from experimental models and clinical evidence on the use of a CEA-based vaccine for the treatment of cancer patients. Among the diverse CEA-based cancer vaccines, DCs- and recombinant viruses-based vaccines seem the most valid. However, although vaccination was shown to induce a strong immune response to CEA, resulting in a delay in tumor progression and prolonged survival in some cancer patients, it failed to eradicate the tumor in most cases, owing partly to the negative effect exerted by the tumor microenvironment on immune response. Thus, in order to develop more efficient and effective cancer vaccines, it is necessary to design new clinical trials combining cancer vaccines with chemotherapy, radiotherapy and drugs which target those factors responsible for immunosuppression of immune cells. This review also discusses relevant patents relating to the use of CEA as a cancer vaccine.

Cure of mammary carcinomas in Her-2 transgenic mice through sequential stimulation of innate (neoadjuvant interleukin-12) and adaptive (DNA vaccine electroporation) immunity.

PURPOSE: Whereas neoadjuvant therapy is emerging as a treatment option in early primary breast cancer, no data are available on the use of antiangiogenic and immunomodulatory agents in a neoadjuvant setting. In a model of Her-2 spontaneous mammary cancer, we investigated the efficacy of neoadjuvant interleukin 12 (IL-12) followed by "immune-surgery" of the residual tumor. EXPERIMENTAL DESIGN: Female BALB/c mice transgenic for the rat Her-2 oncogene inexorably develop invasive carcinomas in all their mammary glands by the 23rd week of age. Mice with multifocal in situ carcinomas received four weekly i.p. injections of 100 ng IL-12 followed by a 3-week rest. This course was given four times. A few mice additionally received DNA plasmids encoding portions of the Her-2 receptor electroporated through transcutaneous electric pulses. RESULTS: The protection elicited by IL-12 in combination with two DNA vaccine electroporations kept 63% of mice tumor-free. Complete protection of all 1-year-old mice was achieved when IL-12-treated mice received four vaccine electroporations. Pathologic findings, in vitro tests, and the results from immunization of both IFN-gamma and immunoglobulin gene knockout transgenic mice and of adoptive transfer experiments all show that IL-12 augments the B- and T-cell response elicited by vaccination and slightly decreases the number of regulatory T cells. In addition, IL-12 strongly inhibits tumor angiogenesis. CONCLUSIONS: In Her-2 transgenic mice, IL-12 impairs tumor progression and triggers innate immunity so markedly that DNA vaccination becomes effective at late points in time when it is ineffective on its own.

Beta-catenin accumulates in intercalated disks of hypertrophic cardiomyopathic hearts.

OBJECTIVE: To evaluate whether cardiomyocyte membrane structure and cell/extracellular matrix adhesion alterations perturb the cadherin/catenin complex in the hypertrophic cardiomyopathy (HCM). METHODS: Hypertrophic cardiomyopathic hamster (UM-X7.1 strain) and human hearts were studied by light and electron microscopy, Northern and Western blot analyses and immunohistochemistry. RESULTS: Intercalated disks are disorganized in both hamster and human cardiomyopathic hearts; beta-catenin is increased and accumulated in intercalated disks depriving cardiomyocyte nuclei of fundamental signals. The accumulation of beta-catenin is post-translationally regulated by an increased Wnt expression, a simultaneous decrease in glycogen synthase kinase 3beta (GSK3beta) expression and a different expression pattern of adenomatous polyposis coli (APC) isoforms. CONCLUSION: The reorganization of cell/cell adhesion in cardiomyopathic hearts is mainly contributed by the cadherin/catenin system, which is differently regulated to sustain cell structural rather than signalling needs causing considerable consequences in the determination of cardiomyocyte phenotype and clinical outcome. The accumulation of beta-catenin in intercalated disks could concur to increase myocardial wall stiffness and left ventricular end-diastolic pressure (LVEDP) in hypertrophic cardiomyopathic hamster and human hearts.