Roberto Bei - Academia.edu (original) (raw)

Papers by Roberto Bei

Research paper thumbnail of Gene-specific inhibition of breast carcinoma in BALB-neuT mice by active immunization with rat Neu or human ErbB receptors

Employing the transgenic BALB-neuT mouse tumor model, we explored the in vivo biologic relevance ... more Employing the transgenic BALB-neuT mouse tumor model, we explored the in vivo biologic relevance of immunocompetent epitopes shared among the four ErbB receptors. The outcome of neu-mediated tumorigenesis was compared following vaccination with isogeneic normal rat ErbB2/Neu (LTR-Neu) or xenogeneic human ErbB receptors (LTR-EGFR, LTR-ErbB2, LTR-ErbB3 and LTR-ErbB4), each recombinantly expressed in an NIH3T3 murine cell background. Vaccination using rat LTR-Neu at the stage of atypical hyperplasia potently inhibited neu-mediated mammary tumorigenesis. Moreover, all human ErbB receptors specifically interfered with tumor development in BALB-neuT mice. Relative increase in tumor-free survival and reduction in tumor incidence corresponded to structural similarity shared with the etiologic neu oncogene, as rat orthologue LTR-Neu proved most effective followed by the human homologue LTR-ErbB2 and the other three human ErbB receptors. Vaccination resulted in high titer specific serum antib...

Research paper thumbnail of Proteasome inhibition by bortezomib parallels a reduction in head and neck cancer cells growth, and an increase in tumor-infiltrating immune cells

Scientific Reports, 2021

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance ... more Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy. Thus, the use of innovative therapeutic drugs is being assessed. Bortezomib is a proteasome inhibitor with anticancer effects. In vitro antitumoral activity of Bortezomib was investigated employing human tongue (SCC-15, CAL-27), pharynx (FaDu), salivary gland (A-253) cancer cell lines and a murine cell line (SALTO-5) originated from a salivary gland adenocarcinoma arising in BALB-neuT male mice transgenic for the oncogene neu. Bortezomib inhibited cell proliferation, triggered apoptosis, modulated the expression and activation of pro-survival signaling transduction pathways proteins activated by ErbB receptors and inhibited proteasome activity in vitro. Intraperitoneal administration of Bortezomib delayed tumor growth of SALTO-5 cells transplanted in BALB-neuT mice, protracted mice survival and adjusted tumor microenvironment by increasing tumor-infiltrating imm...

Research paper thumbnail of In Vitro and In Vivo Anti-tumoral Effects of the Flavonoid Apigenin in Malignant Mesothelioma

Frontiers in pharmacology, 2017

Malignant mesothelioma (MM) is a tumor arising from mesothelium. MM patients' survival is poo... more Malignant mesothelioma (MM) is a tumor arising from mesothelium. MM patients' survival is poor. The polyphenol 4',5,7,-trihydroxyflavone Apigenin (API) is a "multifunctional drug". Several studies have demonstrated API anti-tumoral effects. However, little is known on the in vitro and in vivo anti-tumoral effects of API in MM. Thus, we analyzed the in vitro effects of API on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis, and autophagy of human and mouse MM cells. We evaluated the in vivo anti-tumor activities of API in mice transplanted with MM #40a cells forming ascites. API inhibited in vitro MM cells survival, increased reactive oxygen species intracellular production and induced DNA damage. API activated apoptosis but not autophagy. API-induced apoptosis was sustained by the increase of Bax/Bcl-2 ratio, increase of p53 expression, activation of both caspase 9 and caspase 8, cleavage of PARP-1, and increase of the percenta...

Research paper thumbnail of (±)-Gossypol induces apoptosis and autophagy in head and neck carcinoma cell lines and inhibits the growth of transplanted salivary gland cancer cells in BALB/cmice

International Journal of Food Sciences and Nutrition, 2016

Bei (2016): (±)-Gossypol induces apoptosis and autophagy in head and neck carcinoma cell lines an... more Bei (2016): (±)-Gossypol induces apoptosis and autophagy in head and neck carcinoma cell lines and inhibits the growth of transplanted salivary gland cancer cells in BALB/c mice, International Journal of Food Sciences and Nutrition,

Research paper thumbnail of In vitro and in vivo inhibition of breast cancer cell growth by targeting the Hedgehog/GLI pathway with SMO (GDC-0449) or GLI (GANT-61) inhibitors

Oncotarget, Jan 28, 2016

Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has been implicated in cancer p... more Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has been implicated in cancer progression. Here, we analyzed GLI1, Sonic Hedgehog (Shh) and NF-κB expression in 51 breast cancer (ductal carcinoma) tissues using immunohistochemistry. We found a positive correlation between nuclear GLI1 expression and tumor grade in ductal carcinoma cases. Cytoplasmic Shh staining significantly correlated with a lower tumor grade. Next, the in vitro effects of two Hh signaling pathway inhibitors on breast cancer cell lines were evaluated using the Smoothened (SMO) antagonist GDC-0449 and the direct GLI1 inhibitor GANT-61. GDC-0449 and GANT-61 exhibited the following effects: a) inhibited breast cancer cell survival; b) induced apoptosis; c) inhibited Hh pathway activity by decreasing the mRNA expression levels of GLI1 and Ptch and inhibiting the nuclear translocation of GLI1; d) increased/decreased EGFR and ErbB2 protein expression, reduced p21-Ras and ERK1/ERK2 MAPK activities and in...

Research paper thumbnail of In Vitro and in Vivo Antitumoral Effects of Combinations of Polyphenols, or Polyphenols and Anticancer Drugs: Perspectives on Cancer Treatment

International Journal of Molecular Sciences, 2015

Carcinogenesis is a multistep process triggered by genetic alterations that activate different si... more Carcinogenesis is a multistep process triggered by genetic alterations that activate different signal transduction pathways and cause the progressive transformation of a normal cell into a cancer cell. Polyphenols, compounds ubiquitously expressed in plants, have anti-inflammatory, antimicrobial, antiviral, anticancer, and immunomodulatory properties, all of which are beneficial to human health. Due to their ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression, polyphenols can be employed to inhibit the growth of cancer cells. However, the main problem related to the use of polyphenols as anticancer agents is their poor bioavailability, which might hinder the in vivo effects of the single compound. In fact, polyphenols have a poor absorption and biodistribution, but also a fast metabolism and excretion in the human body. The poor bioavailability of a polyphenol will affect the effective dose delivered to cancer cells. One way to counteract this drawback could be combination treatment with different polyphenols or with polyphenols and other anti-cancer drugs, which can lead to more effective antitumor effects than treatment using only one

Research paper thumbnail of The ribosomal P0 protein induces a spontaneous immune response in patients with head and neck advanced stage carcinoma that is not dependent on its overexpression in carcinomas

International Journal of Oncology, 2007

A typical feature in systemic lupus erythemathosus patients is the presence of autoantibodies to ... more A typical feature in systemic lupus erythemathosus patients is the presence of autoantibodies to the carboxylterminal homologous P proteins (P0, P1, P2) domain (C-22 P0 epitope). In this report we provide evidence for the in vivo immunogenicity of the P0 protein in head and neck cancer patients as well as overexpression by immunohistochemistry of the C-22 P0 epitope in invasive carcinomas (55/57). Overexpression of this epitope was also significantly associated with a number of pathological lesions arising in the head and neck stratified epithelium including acanthosis (8/8), benign tumors (11/11), dysplasia (23/25) and in situ carcinomas (9/9). Intermediate cell layer restricted epitope overexpression was observed in well differentiated carcinomas, while undifferentiated tumors showed overexpression throughout the cell layers. Employing recombinant P proteins, sera from 40 of the 57 carcinoma patients and 39 normal donors, were subjected to immunoblot analysis. Immunity to P0 protein (7/40) was associated with malignancy and with advanced disease stage, but it was not dependent on the C-22 P0 epitope overexpression, although it was the preferential autoantibody target in 4 patients. Increased expression of the C-22 P0 epitope on the surface of pharynx cancer cells following cellular stress in vitro, may imply P0 protein presentation as an in vivo autoantibody target in cancer patients. Evidence for immunity to the P0 protein, as well as overexpression in patients with head and neck carcinoma may be relevant for monitoring cancer progression, in planning immunotherapeutic strategies, and contribute to the understanding of immuno-biological behaviour of head and neck carcinomas.

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

Oncotarget, Jan 15, 2014

The survival rate of head and neck squamous cell carcinomas (HNSCC) patients has not considerably... more 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 transp...

Research paper thumbnail of 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

Oncology Reports, 2012

Prostate cancer is a common cancer among men in developed countries. Although hormonotherapy and ... more 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.

Research paper thumbnail of Immune responses to all ErbB family receptors detectable in serum of cancer patients

Oncogene, 1999

Employing NIH3T3 transfectants with individual human ErbB receptor coding sequences as recombinan... more Employing NIH3T3 transfectants with individual human ErbB receptor coding sequences as recombinant antigen sources, we detected by immunoblot analysis speci®c immunoreactivity against all four ErbB receptors among 13 of 41 sera obtained from patients with dierent types of epithelial malignancies. Overall, serum positivity was most frequently directed against ErbB2 followed by EGFR, ErbB3 and ErbB4. Speci®city patterns comprised tumor patients with unique serum reactivity against ErbB2 or ErbB4. Moreover, approximately half of the positive sera exhibited concomitant reactivity with multiple ErbB receptors including EGFR and ErbB2, EGFR and ErbB4, ErbB2 and ErbB3 or EGFR, ErbB2 and ErbB3. Serum reactivity was con®rmed for the respective ErbB receptors expressed by human tumor cells and corroborated on receptor-speci®c immunoprecipitates. Positive sera contained ErbB-speci®c antibodies of the IgG isotype. Representative immunohistochemical analysis of tumor tissues suggested overexpression of ErbB receptors for which serum antibodies were detectable in ®ve of six patients. These ®ndings implicate multiple ErbB receptors including ErbB3 and ErbB4 in addition to EGFR and ErbB2 in primary human cancer. Heterogeneity of natural ErbB-speci®c responses in cancer patients warrants their evaluation in light of immunotherapeutic approaches targeting these receptors.

Research paper thumbnail of The BFRF1 Gene of Epstein-Barr Virus Encodes a Novel Protein

Journal of Virology, 2000

Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading fr... more Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The Bam HI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in the Bam HI F region ( BFRF1 ). Histidine and glutathione S -transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 M...

Research paper thumbnail of The BFRF1 Gene of Epstein-Barr Virus Encodes a Novel Protein

Journal of Virology, 2000

Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading fr... more Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The Bam HI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in the Bam HI F region ( BFRF1 ). Histidine and glutathione S -transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 M...

Research paper thumbnail of Frequent overexpression of multiple ErbB receptors by head and neck squamous cell carcinoma contrasts with rare antibody immunity in patients

The Journal of Pathology, 2004

In an effort to elucidate the role of ErbB receptors in human head and neck squamous cell carcino... more In an effort to elucidate the role of ErbB receptors in human head and neck squamous cell carcinoma (HNSCC), expression abnormalities and subcellular localization of epidermal growth factor receptor (EGFR), ErbB2, ErbB3, and ErbB4 were investigated along with EGF and tenascin by immunohistochemistry in 38 carcinomas as compared to adjacent normal mucosa of 24 cases. Although tumour-specific overexpression affected each ErbB receptor (EGFR 47%, ErbB2 29%, ErbB3 21%, ErbB4 26%), EGFR abnormalities were most prevalent. The latter, and overexpression of more than two ErbB receptors in the same tumour, which always included EGFR, correlated with metastatic disease. ErbB products were specifically detected on the cell membrane and in the cytoplasm. In contrast, ErbB4 was uniquely localized to the nucleus in 7 carcinomas and a tumour-derived cell line, indicating a role for regulated intramembrane proteolysis resulting in nuclear ErbB4 translocation in HNSCC. Expression of prototype ligand EGF or low-affinity stromal activator tenascin correlated significantly with EGFR overexpression, implying chronic EGFR activation. Simultaneous overexpression of additional ErbB receptors in most of these cases suggested recurrent involvement of receptor heterodimers. In spite of frequent ErbB receptor alterations, autologous ErbB serum antibodies were rare, with only 1 of 38 tumour patients exhibiting an ErbB2-specific immune response. Based on upregulation of several known immunosuppressive molecules, scarcity of ErbB-specific antibodies is consistent with attenuation of natural tumour-specific immune responses in HNSCC.

Research paper thumbnail of Co-localization of multiple ErbB receptors in stratified epithelium of oral squamous cell carcinoma

The Journal of Pathology, 2001

The expression of all four ErbB receptors was compared by immunohistochemistry, using receptor-sp... more The expression of all four ErbB receptors was compared by immunohistochemistry, using receptor-specific polyclonal antisera, in 32 invasive, 11 in situ carcinomas, six benign lesions, and 22 samples of histologically normal mucosa adjacent to specimens of carcinoma originating from oral cavity epithelium. Among invasive and in situ carcinoma, EGFR expression was the most prevalent (in 29/32 and 8/11 cases, respectively) followed by ErbB2 (17/32 and 2/11) and ErbB4 (9/32 and 1/10), while ErbB3 was only detected in invasive tumours (12/32). Specific patterns included invasive tumours with expression of EGFR (8/32) or ErbB4 (1/32) alone, as well as different receptor combinations (EGFR+ErbB2, EGFR+ErbB4, EGFR+ErbB2+ErbB3, EGFR+ErbB2+ErbB4, and all four receptors). Simultaneous expression of three or four ErbB receptors correlated with tumour invasion (p=2.2r10 x4) and localized in the intermediate epithelial cell layer of well and moderately differentiated tumours. No other significant correlation with clinico-pathological features was noticed. Some benign lesions and histologically normal mucosa adjacent to carcinomas showed weak immunostaining of EGFR (10/28), ErbB2 (4/28) or ErbB4 (3/28). By comparison, overexpression, as indicated by increased staining intensity, was observed in invasive tumours for EGFR (18/32), ErbB2 (8/32), ErbB4 (3/32), and ErbB3 (3/32). Statistical evaluation demonstrated a significant association of EGFR or ErbB2 overexpression with invasive carcinoma when compared with benign lesions and apparently normal epithelium (p=5.2r10 x7 and p=5r10 x3 , respectively). Tumour-specific overexpression of ErbB receptors and their co-expression, most frequently involving EGFR and ErbB2, in the same cell layer of neoplastic epithelium, implicate receptor heterodimers in the pathogenesis of oral squamous carcinoma.

Research paper thumbnail of Intracellular localization of the Epstein-Barr virus BFRF1 gene product in lymphoid cell lines and oral hairy leukoplakia lesions

Journal of Medical Virology, 2003

Research paper thumbnail of The Use of a Cationic Liposome Formulation (DOTAP) Mixed with a Recombinant Tumor-Associated Antigen to Induce Immune Responses and Protective Immunity in Mice

Journal of Immunotherapy, 1998

Despite the fact that mice d o not express CEA or NCA (nonspecific cross-reacting antigen, a gene... more Despite the fact that mice d o not express CEA or NCA (nonspecific cross-reacting antigen, a gene related t o CEA), a transplant with syngeneic tumor cells transduced with the human CEA gene is not rejected. These tumor-bearing mice develop only a low titer of anti-CEA antibodies (2). Few reports describe the generation of CEA-specific cytotoxic T-lymphocytes (CTLs) in mice. This was achieved only when three immunizations of a recombinant vaccinia virus expressing CEA (rV-CEA) were administered to mice (3,4). Immunizations with purified native CEA emulsified in complete Freund's ad

Research paper thumbnail of DNA Vaccination Against Rat Her-2/Neu p185 More Effectively Inhibits Carcinogenesis Than Transplantable Carcinomas in Transgenic BALB/c Mice

The Journal of Immunology, 2000

Research paper thumbnail of Caveolin-1 overexpression is associated with simultaneous abnormal expression of the E-cadherin/α-β catenins complex and multiple erbb receptors and with lymph nodes metastasis in head and neck squamous cell carcinomas

Journal of Cellular Physiology, 2012

The presence of lymph node metastases is one of the most important prognostic indicators in head ... more The presence of lymph node metastases is one of the most important prognostic indicators in head and neck squamous cell carcinomas (HNSCCs). An alteration of the E-cadherin-catenins complex and EGFR is essential for the invasiveness of cancer cells. Caveolin-1, the major structural protein of the caveolae, represents a scaffolding molecule for several signaling proteins including EGFR. Although caveolin-1 has been shown to play a role in inducing the invasive phenotype of cancer cells, its role appears to be cell-type specific and for some tumors it has not been defined yet. In this study we used 57 HNSCC specimens to investigate whether the abnormal expression of caveolin-1 was associated with the derangement of the E-cadherin-catenins complex and with the overexpression of ErbB receptors. We demonstrate that in HNSCCs caveolin-1 overexpression is associated with the simultaneous abnormal expression of at least one member of the E-cadherin/a-b catenins complex and multiple ErbB receptors as well as with lymph node metastases. We also demonstrate that chronic stimulation of a human hypopharyngeal carcinoma cell line (FaDu) with EGF induced the internalization of b-catenin and caveolin-1 and their co-localization with EGFR. Moreover, EGF treatment induced an increased physical interaction between EGFR/b-catenin/ caveolin-1 and between E-cadherin/b-catenin/caveolin-1. These molecular events were associated with an increased directional motility of FaDu cells in vitro. These findings may provide new insight into the biology of HNSCC progression and help to identify subgroups of primary HNSCCs with a more aggressive behavior.

Research paper thumbnail of Caveolin-1 overexpression is associated with simultaneous abnormal expression of the E-cadherin/α-β catenins complex and multiple erbb receptors and with lymph nodes metastasis in head and neck squamous cell carcinomas

Journal of Cellular Physiology, 2012

The presence of lymph node metastases is one of the most important prognostic indicators in head ... more The presence of lymph node metastases is one of the most important prognostic indicators in head and neck squamous cell carcinomas (HNSCCs). An alteration of the E-cadherin-catenins complex and EGFR is essential for the invasiveness of cancer cells. Caveolin-1, the major structural protein of the caveolae, represents a scaffolding molecule for several signaling proteins including EGFR. Although caveolin-1 has been shown to play a role in inducing the invasive phenotype of cancer cells, its role appears to be cell-type specific and for some tumors it has not been defined yet. In this study we used 57 HNSCC specimens to investigate whether the abnormal expression of caveolin-1 was associated with the derangement of the E-cadherin-catenins complex and with the overexpression of ErbB receptors. We demonstrate that in HNSCCs caveolin-1 overexpression is associated with the simultaneous abnormal expression of at least one member of the E-cadherin/a-b catenins complex and multiple ErbB receptors as well as with lymph node metastases. We also demonstrate that chronic stimulation of a human hypopharyngeal carcinoma cell line (FaDu) with EGF induced the internalization of b-catenin and caveolin-1 and their co-localization with EGFR. Moreover, EGF treatment induced an increased physical interaction between EGFR/b-catenin/ caveolin-1 and between E-cadherin/b-catenin/caveolin-1. These molecular events were associated with an increased directional motility of FaDu cells in vitro. These findings may provide new insight into the biology of HNSCC progression and help to identify subgroups of primary HNSCCs with a more aggressive behavior.

Research paper thumbnail of TAA Polyepitope DNA-Based Vaccines: A Potential Tool for Cancer Therapy

Journal of Biomedicine and Biotechnology, 2010

DNA-based cancer vaccines represent an attractive strategy for inducing immunity to tumor associa... more DNA-based cancer vaccines represent an attractive strategy for inducing immunity to tumor associated antigens (TAAs) in cancer patients. The demonstration that the delivery of a recombinant plasmid encoding epitopes can lead to epitope production, processing, and presentation to CD8+ T-lymphocytes, and the advantage of using a single DNA construct encoding multiple epitopes of one or more TAAs to elicit a broad spectrum of cytotoxic T-lymphocytes has encouraged the development of a variety of strategies aimed at increasing immunogenicity of TAA polyepitope DNA-based vaccines. The polyepitope DNA-based cancer vaccine approach can (a) circumvent the variability of peptide presentation by tumor cells, (b) allow the introduction in the plasmid construct of multiple immunogenic epitopes including heteroclitic epitope versions, and (c) permit to enroll patients with different major histocompatibility complex (MHC) haplotypes. This review will discuss the rationale for using the TAA polyep...

Research paper thumbnail of Gene-specific inhibition of breast carcinoma in BALB-neuT mice by active immunization with rat Neu or human ErbB receptors

Employing the transgenic BALB-neuT mouse tumor model, we explored the in vivo biologic relevance ... more Employing the transgenic BALB-neuT mouse tumor model, we explored the in vivo biologic relevance of immunocompetent epitopes shared among the four ErbB receptors. The outcome of neu-mediated tumorigenesis was compared following vaccination with isogeneic normal rat ErbB2/Neu (LTR-Neu) or xenogeneic human ErbB receptors (LTR-EGFR, LTR-ErbB2, LTR-ErbB3 and LTR-ErbB4), each recombinantly expressed in an NIH3T3 murine cell background. Vaccination using rat LTR-Neu at the stage of atypical hyperplasia potently inhibited neu-mediated mammary tumorigenesis. Moreover, all human ErbB receptors specifically interfered with tumor development in BALB-neuT mice. Relative increase in tumor-free survival and reduction in tumor incidence corresponded to structural similarity shared with the etiologic neu oncogene, as rat orthologue LTR-Neu proved most effective followed by the human homologue LTR-ErbB2 and the other three human ErbB receptors. Vaccination resulted in high titer specific serum antib...

Research paper thumbnail of Proteasome inhibition by bortezomib parallels a reduction in head and neck cancer cells growth, and an increase in tumor-infiltrating immune cells

Scientific Reports, 2021

Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance ... more Head and neck cancer (HNC) has frequently an aggressive course for the development of resistance to standard chemotherapy. Thus, the use of innovative therapeutic drugs is being assessed. Bortezomib is a proteasome inhibitor with anticancer effects. In vitro antitumoral activity of Bortezomib was investigated employing human tongue (SCC-15, CAL-27), pharynx (FaDu), salivary gland (A-253) cancer cell lines and a murine cell line (SALTO-5) originated from a salivary gland adenocarcinoma arising in BALB-neuT male mice transgenic for the oncogene neu. Bortezomib inhibited cell proliferation, triggered apoptosis, modulated the expression and activation of pro-survival signaling transduction pathways proteins activated by ErbB receptors and inhibited proteasome activity in vitro. Intraperitoneal administration of Bortezomib delayed tumor growth of SALTO-5 cells transplanted in BALB-neuT mice, protracted mice survival and adjusted tumor microenvironment by increasing tumor-infiltrating imm...

Research paper thumbnail of In Vitro and In Vivo Anti-tumoral Effects of the Flavonoid Apigenin in Malignant Mesothelioma

Frontiers in pharmacology, 2017

Malignant mesothelioma (MM) is a tumor arising from mesothelium. MM patients' survival is poo... more Malignant mesothelioma (MM) is a tumor arising from mesothelium. MM patients' survival is poor. The polyphenol 4',5,7,-trihydroxyflavone Apigenin (API) is a "multifunctional drug". Several studies have demonstrated API anti-tumoral effects. However, little is known on the in vitro and in vivo anti-tumoral effects of API in MM. Thus, we analyzed the in vitro effects of API on cell proliferation, cell cycle regulation, pro-survival signaling pathways, apoptosis, and autophagy of human and mouse MM cells. We evaluated the in vivo anti-tumor activities of API in mice transplanted with MM #40a cells forming ascites. API inhibited in vitro MM cells survival, increased reactive oxygen species intracellular production and induced DNA damage. API activated apoptosis but not autophagy. API-induced apoptosis was sustained by the increase of Bax/Bcl-2 ratio, increase of p53 expression, activation of both caspase 9 and caspase 8, cleavage of PARP-1, and increase of the percenta...

Research paper thumbnail of (±)-Gossypol induces apoptosis and autophagy in head and neck carcinoma cell lines and inhibits the growth of transplanted salivary gland cancer cells in BALB/cmice

International Journal of Food Sciences and Nutrition, 2016

Bei (2016): (±)-Gossypol induces apoptosis and autophagy in head and neck carcinoma cell lines an... more Bei (2016): (±)-Gossypol induces apoptosis and autophagy in head and neck carcinoma cell lines and inhibits the growth of transplanted salivary gland cancer cells in BALB/c mice, International Journal of Food Sciences and Nutrition,

Research paper thumbnail of In vitro and in vivo inhibition of breast cancer cell growth by targeting the Hedgehog/GLI pathway with SMO (GDC-0449) or GLI (GANT-61) inhibitors

Oncotarget, Jan 28, 2016

Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has been implicated in cancer p... more Aberrant Hedgehog (Hh)/glioma-associated oncogene (GLI) signaling has been implicated in cancer progression. Here, we analyzed GLI1, Sonic Hedgehog (Shh) and NF-κB expression in 51 breast cancer (ductal carcinoma) tissues using immunohistochemistry. We found a positive correlation between nuclear GLI1 expression and tumor grade in ductal carcinoma cases. Cytoplasmic Shh staining significantly correlated with a lower tumor grade. Next, the in vitro effects of two Hh signaling pathway inhibitors on breast cancer cell lines were evaluated using the Smoothened (SMO) antagonist GDC-0449 and the direct GLI1 inhibitor GANT-61. GDC-0449 and GANT-61 exhibited the following effects: a) inhibited breast cancer cell survival; b) induced apoptosis; c) inhibited Hh pathway activity by decreasing the mRNA expression levels of GLI1 and Ptch and inhibiting the nuclear translocation of GLI1; d) increased/decreased EGFR and ErbB2 protein expression, reduced p21-Ras and ERK1/ERK2 MAPK activities and in...

Research paper thumbnail of In Vitro and in Vivo Antitumoral Effects of Combinations of Polyphenols, or Polyphenols and Anticancer Drugs: Perspectives on Cancer Treatment

International Journal of Molecular Sciences, 2015

Carcinogenesis is a multistep process triggered by genetic alterations that activate different si... more Carcinogenesis is a multistep process triggered by genetic alterations that activate different signal transduction pathways and cause the progressive transformation of a normal cell into a cancer cell. Polyphenols, compounds ubiquitously expressed in plants, have anti-inflammatory, antimicrobial, antiviral, anticancer, and immunomodulatory properties, all of which are beneficial to human health. Due to their ability to modulate the activity of multiple targets involved in carcinogenesis through direct interaction or modulation of gene expression, polyphenols can be employed to inhibit the growth of cancer cells. However, the main problem related to the use of polyphenols as anticancer agents is their poor bioavailability, which might hinder the in vivo effects of the single compound. In fact, polyphenols have a poor absorption and biodistribution, but also a fast metabolism and excretion in the human body. The poor bioavailability of a polyphenol will affect the effective dose delivered to cancer cells. One way to counteract this drawback could be combination treatment with different polyphenols or with polyphenols and other anti-cancer drugs, which can lead to more effective antitumor effects than treatment using only one

Research paper thumbnail of The ribosomal P0 protein induces a spontaneous immune response in patients with head and neck advanced stage carcinoma that is not dependent on its overexpression in carcinomas

International Journal of Oncology, 2007

A typical feature in systemic lupus erythemathosus patients is the presence of autoantibodies to ... more A typical feature in systemic lupus erythemathosus patients is the presence of autoantibodies to the carboxylterminal homologous P proteins (P0, P1, P2) domain (C-22 P0 epitope). In this report we provide evidence for the in vivo immunogenicity of the P0 protein in head and neck cancer patients as well as overexpression by immunohistochemistry of the C-22 P0 epitope in invasive carcinomas (55/57). Overexpression of this epitope was also significantly associated with a number of pathological lesions arising in the head and neck stratified epithelium including acanthosis (8/8), benign tumors (11/11), dysplasia (23/25) and in situ carcinomas (9/9). Intermediate cell layer restricted epitope overexpression was observed in well differentiated carcinomas, while undifferentiated tumors showed overexpression throughout the cell layers. Employing recombinant P proteins, sera from 40 of the 57 carcinoma patients and 39 normal donors, were subjected to immunoblot analysis. Immunity to P0 protein (7/40) was associated with malignancy and with advanced disease stage, but it was not dependent on the C-22 P0 epitope overexpression, although it was the preferential autoantibody target in 4 patients. Increased expression of the C-22 P0 epitope on the surface of pharynx cancer cells following cellular stress in vitro, may imply P0 protein presentation as an in vivo autoantibody target in cancer patients. Evidence for immunity to the P0 protein, as well as overexpression in patients with head and neck carcinoma may be relevant for monitoring cancer progression, in planning immunotherapeutic strategies, and contribute to the understanding of immuno-biological behaviour of head and neck carcinomas.

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

Oncotarget, Jan 15, 2014

The survival rate of head and neck squamous cell carcinomas (HNSCC) patients has not considerably... more 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 transp...

Research paper thumbnail of 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

Oncology Reports, 2012

Prostate cancer is a common cancer among men in developed countries. Although hormonotherapy and ... more 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.

Research paper thumbnail of Immune responses to all ErbB family receptors detectable in serum of cancer patients

Oncogene, 1999

Employing NIH3T3 transfectants with individual human ErbB receptor coding sequences as recombinan... more Employing NIH3T3 transfectants with individual human ErbB receptor coding sequences as recombinant antigen sources, we detected by immunoblot analysis speci®c immunoreactivity against all four ErbB receptors among 13 of 41 sera obtained from patients with dierent types of epithelial malignancies. Overall, serum positivity was most frequently directed against ErbB2 followed by EGFR, ErbB3 and ErbB4. Speci®city patterns comprised tumor patients with unique serum reactivity against ErbB2 or ErbB4. Moreover, approximately half of the positive sera exhibited concomitant reactivity with multiple ErbB receptors including EGFR and ErbB2, EGFR and ErbB4, ErbB2 and ErbB3 or EGFR, ErbB2 and ErbB3. Serum reactivity was con®rmed for the respective ErbB receptors expressed by human tumor cells and corroborated on receptor-speci®c immunoprecipitates. Positive sera contained ErbB-speci®c antibodies of the IgG isotype. Representative immunohistochemical analysis of tumor tissues suggested overexpression of ErbB receptors for which serum antibodies were detectable in ®ve of six patients. These ®ndings implicate multiple ErbB receptors including ErbB3 and ErbB4 in addition to EGFR and ErbB2 in primary human cancer. Heterogeneity of natural ErbB-speci®c responses in cancer patients warrants their evaluation in light of immunotherapeutic approaches targeting these receptors.

Research paper thumbnail of The BFRF1 Gene of Epstein-Barr Virus Encodes a Novel Protein

Journal of Virology, 2000

Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading fr... more Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The Bam HI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in the Bam HI F region ( BFRF1 ). Histidine and glutathione S -transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 M...

Research paper thumbnail of The BFRF1 Gene of Epstein-Barr Virus Encodes a Novel Protein

Journal of Virology, 2000

Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading fr... more Computer analysis of the Epstein-Barr virus (EBV) genome indicates there are ∼100 open reading frames (ORFs). Thus far about 30 EBV genes divided into the categories latent and lytic have been identified. The Bam HI F region of EBV is abundantly transcribed during lytic replication. This region is highly conserved among herpesviruses, thus suggesting that some common function could be retained in the ORFs encompassed within this viral fragment. To identify putative novel proteins and possible new markers for viral replication, we focused our attention on the first rightward ORF in the Bam HI F region ( BFRF1 ). Histidine and glutathione S -transferase-tagged BFRF1 fusion proteins were synthesized to produce a mouse monoclonal antibody (MAb). Analysis of human sera revealed a high seroprevalence of antibodies to BFRF1 in patients affected by nasopharyngeal carcinoma or Burkitt's lymphoma, whereas no humoral response to BFRF1 could be detected among healthy donors. An anti-BFRF1 M...

Research paper thumbnail of Frequent overexpression of multiple ErbB receptors by head and neck squamous cell carcinoma contrasts with rare antibody immunity in patients

The Journal of Pathology, 2004

In an effort to elucidate the role of ErbB receptors in human head and neck squamous cell carcino... more In an effort to elucidate the role of ErbB receptors in human head and neck squamous cell carcinoma (HNSCC), expression abnormalities and subcellular localization of epidermal growth factor receptor (EGFR), ErbB2, ErbB3, and ErbB4 were investigated along with EGF and tenascin by immunohistochemistry in 38 carcinomas as compared to adjacent normal mucosa of 24 cases. Although tumour-specific overexpression affected each ErbB receptor (EGFR 47%, ErbB2 29%, ErbB3 21%, ErbB4 26%), EGFR abnormalities were most prevalent. The latter, and overexpression of more than two ErbB receptors in the same tumour, which always included EGFR, correlated with metastatic disease. ErbB products were specifically detected on the cell membrane and in the cytoplasm. In contrast, ErbB4 was uniquely localized to the nucleus in 7 carcinomas and a tumour-derived cell line, indicating a role for regulated intramembrane proteolysis resulting in nuclear ErbB4 translocation in HNSCC. Expression of prototype ligand EGF or low-affinity stromal activator tenascin correlated significantly with EGFR overexpression, implying chronic EGFR activation. Simultaneous overexpression of additional ErbB receptors in most of these cases suggested recurrent involvement of receptor heterodimers. In spite of frequent ErbB receptor alterations, autologous ErbB serum antibodies were rare, with only 1 of 38 tumour patients exhibiting an ErbB2-specific immune response. Based on upregulation of several known immunosuppressive molecules, scarcity of ErbB-specific antibodies is consistent with attenuation of natural tumour-specific immune responses in HNSCC.

Research paper thumbnail of Co-localization of multiple ErbB receptors in stratified epithelium of oral squamous cell carcinoma

The Journal of Pathology, 2001

The expression of all four ErbB receptors was compared by immunohistochemistry, using receptor-sp... more The expression of all four ErbB receptors was compared by immunohistochemistry, using receptor-specific polyclonal antisera, in 32 invasive, 11 in situ carcinomas, six benign lesions, and 22 samples of histologically normal mucosa adjacent to specimens of carcinoma originating from oral cavity epithelium. Among invasive and in situ carcinoma, EGFR expression was the most prevalent (in 29/32 and 8/11 cases, respectively) followed by ErbB2 (17/32 and 2/11) and ErbB4 (9/32 and 1/10), while ErbB3 was only detected in invasive tumours (12/32). Specific patterns included invasive tumours with expression of EGFR (8/32) or ErbB4 (1/32) alone, as well as different receptor combinations (EGFR+ErbB2, EGFR+ErbB4, EGFR+ErbB2+ErbB3, EGFR+ErbB2+ErbB4, and all four receptors). Simultaneous expression of three or four ErbB receptors correlated with tumour invasion (p=2.2r10 x4) and localized in the intermediate epithelial cell layer of well and moderately differentiated tumours. No other significant correlation with clinico-pathological features was noticed. Some benign lesions and histologically normal mucosa adjacent to carcinomas showed weak immunostaining of EGFR (10/28), ErbB2 (4/28) or ErbB4 (3/28). By comparison, overexpression, as indicated by increased staining intensity, was observed in invasive tumours for EGFR (18/32), ErbB2 (8/32), ErbB4 (3/32), and ErbB3 (3/32). Statistical evaluation demonstrated a significant association of EGFR or ErbB2 overexpression with invasive carcinoma when compared with benign lesions and apparently normal epithelium (p=5.2r10 x7 and p=5r10 x3 , respectively). Tumour-specific overexpression of ErbB receptors and their co-expression, most frequently involving EGFR and ErbB2, in the same cell layer of neoplastic epithelium, implicate receptor heterodimers in the pathogenesis of oral squamous carcinoma.

Research paper thumbnail of Intracellular localization of the Epstein-Barr virus BFRF1 gene product in lymphoid cell lines and oral hairy leukoplakia lesions

Journal of Medical Virology, 2003

Research paper thumbnail of The Use of a Cationic Liposome Formulation (DOTAP) Mixed with a Recombinant Tumor-Associated Antigen to Induce Immune Responses and Protective Immunity in Mice

Journal of Immunotherapy, 1998

Despite the fact that mice d o not express CEA or NCA (nonspecific cross-reacting antigen, a gene... more Despite the fact that mice d o not express CEA or NCA (nonspecific cross-reacting antigen, a gene related t o CEA), a transplant with syngeneic tumor cells transduced with the human CEA gene is not rejected. These tumor-bearing mice develop only a low titer of anti-CEA antibodies (2). Few reports describe the generation of CEA-specific cytotoxic T-lymphocytes (CTLs) in mice. This was achieved only when three immunizations of a recombinant vaccinia virus expressing CEA (rV-CEA) were administered to mice (3,4). Immunizations with purified native CEA emulsified in complete Freund's ad

Research paper thumbnail of DNA Vaccination Against Rat Her-2/Neu p185 More Effectively Inhibits Carcinogenesis Than Transplantable Carcinomas in Transgenic BALB/c Mice

The Journal of Immunology, 2000

Research paper thumbnail of Caveolin-1 overexpression is associated with simultaneous abnormal expression of the E-cadherin/α-β catenins complex and multiple erbb receptors and with lymph nodes metastasis in head and neck squamous cell carcinomas

Journal of Cellular Physiology, 2012

The presence of lymph node metastases is one of the most important prognostic indicators in head ... more The presence of lymph node metastases is one of the most important prognostic indicators in head and neck squamous cell carcinomas (HNSCCs). An alteration of the E-cadherin-catenins complex and EGFR is essential for the invasiveness of cancer cells. Caveolin-1, the major structural protein of the caveolae, represents a scaffolding molecule for several signaling proteins including EGFR. Although caveolin-1 has been shown to play a role in inducing the invasive phenotype of cancer cells, its role appears to be cell-type specific and for some tumors it has not been defined yet. In this study we used 57 HNSCC specimens to investigate whether the abnormal expression of caveolin-1 was associated with the derangement of the E-cadherin-catenins complex and with the overexpression of ErbB receptors. We demonstrate that in HNSCCs caveolin-1 overexpression is associated with the simultaneous abnormal expression of at least one member of the E-cadherin/a-b catenins complex and multiple ErbB receptors as well as with lymph node metastases. We also demonstrate that chronic stimulation of a human hypopharyngeal carcinoma cell line (FaDu) with EGF induced the internalization of b-catenin and caveolin-1 and their co-localization with EGFR. Moreover, EGF treatment induced an increased physical interaction between EGFR/b-catenin/ caveolin-1 and between E-cadherin/b-catenin/caveolin-1. These molecular events were associated with an increased directional motility of FaDu cells in vitro. These findings may provide new insight into the biology of HNSCC progression and help to identify subgroups of primary HNSCCs with a more aggressive behavior.

Research paper thumbnail of Caveolin-1 overexpression is associated with simultaneous abnormal expression of the E-cadherin/α-β catenins complex and multiple erbb receptors and with lymph nodes metastasis in head and neck squamous cell carcinomas

Journal of Cellular Physiology, 2012

The presence of lymph node metastases is one of the most important prognostic indicators in head ... more The presence of lymph node metastases is one of the most important prognostic indicators in head and neck squamous cell carcinomas (HNSCCs). An alteration of the E-cadherin-catenins complex and EGFR is essential for the invasiveness of cancer cells. Caveolin-1, the major structural protein of the caveolae, represents a scaffolding molecule for several signaling proteins including EGFR. Although caveolin-1 has been shown to play a role in inducing the invasive phenotype of cancer cells, its role appears to be cell-type specific and for some tumors it has not been defined yet. In this study we used 57 HNSCC specimens to investigate whether the abnormal expression of caveolin-1 was associated with the derangement of the E-cadherin-catenins complex and with the overexpression of ErbB receptors. We demonstrate that in HNSCCs caveolin-1 overexpression is associated with the simultaneous abnormal expression of at least one member of the E-cadherin/a-b catenins complex and multiple ErbB receptors as well as with lymph node metastases. We also demonstrate that chronic stimulation of a human hypopharyngeal carcinoma cell line (FaDu) with EGF induced the internalization of b-catenin and caveolin-1 and their co-localization with EGFR. Moreover, EGF treatment induced an increased physical interaction between EGFR/b-catenin/ caveolin-1 and between E-cadherin/b-catenin/caveolin-1. These molecular events were associated with an increased directional motility of FaDu cells in vitro. These findings may provide new insight into the biology of HNSCC progression and help to identify subgroups of primary HNSCCs with a more aggressive behavior.

Research paper thumbnail of TAA Polyepitope DNA-Based Vaccines: A Potential Tool for Cancer Therapy

Journal of Biomedicine and Biotechnology, 2010

DNA-based cancer vaccines represent an attractive strategy for inducing immunity to tumor associa... more DNA-based cancer vaccines represent an attractive strategy for inducing immunity to tumor associated antigens (TAAs) in cancer patients. The demonstration that the delivery of a recombinant plasmid encoding epitopes can lead to epitope production, processing, and presentation to CD8+ T-lymphocytes, and the advantage of using a single DNA construct encoding multiple epitopes of one or more TAAs to elicit a broad spectrum of cytotoxic T-lymphocytes has encouraged the development of a variety of strategies aimed at increasing immunogenicity of TAA polyepitope DNA-based vaccines. The polyepitope DNA-based cancer vaccine approach can (a) circumvent the variability of peptide presentation by tumor cells, (b) allow the introduction in the plasmid construct of multiple immunogenic epitopes including heteroclitic epitope versions, and (c) permit to enroll patients with different major histocompatibility complex (MHC) haplotypes. This review will discuss the rationale for using the TAA polyep...