Pharmacological inhibition of HSP90 and ras activity as a new strategy in the treatment of HNSCC.

Advanced head and neck squamous cell cancer (HNSCC) is currently treated with taxane-based chemotherapy. We have previously shown that docetaxel (DTX) induces a ras-dependent survival signal that can be antagonized by farnesyl transferase inhibitors (FTI) such as tipifarnib (TIP). Here we show that the synergistic TIP/DTX combination determines synergistic apoptotic conditions but, at the same time, it modulates the expression of the components of the multichaperone complex that is, in turn, involved in the regulation of the stability of members of the ras-mediated pathway. Therefore, we have stably transfected HNSCC KB and Hep-2 cells with a plasmid encoding for HSP90. The expression of the protein was increased in both transfected cell lines but its activation status was increased in Hep-2 clones and decreased in KB clones. On the basis of these results, we have treated both parental and HSP90-transfected cells with a HSP90 inhibitor geldanamycin (GA). We have found that the antiproliferative activity of GA is dependent upon the activation status of HSP90 and that it is strongly synergistic when added in combination with TIP but not with DTX in cells overexpressing HSP90 and even more in cells with increased HSP90 activity. These data were paralleled by the decreased expression and activity of the components belonging to the ras→mediated signal transduction pathway. The present results suggest that multichaperone complex activation could be a resistance mechanism to the anti-proliferative and apoptotic effects induced by TIP and that the combination of FTIs such as TIP with GA could be a suitable therapeutic strategy in the treatment of HSP90-overexpressing HNSCC.

Transglutaminases: key regulators of cancer metastasis.

The ability to metastasize represents the most important characteristic of malignant tumors. The biological details of the metastatic process remain somewhat unknown, due to difficulties in studying tumor cell behaviour with high spatial and temporal resolution in vivo. Several lines of evidence involve transglutaminases (TGs) in the key stages of tumor progression cascade, even though the molecular mechanisms remain controversial. TG expression and activity display a different role in the primary tumor or in metastatic cells. In fact, TG expression is low in the primary tumor mass, but augmented when cells acquire the metastatic phenotype. Nevertheless, in other cases, the use of inducers of TG transamidating activity seems to contrast tumor cell plasticity, migration and invasion. In the following review, the function of TGs in cancer cell migration into the extracellular matrix, adhesion to the capillary endothelium and its basement membrane, invasion and angiogenesis is discussed.

Type I interferons: ancient peptides with still under-discovered anti-cancer properties.

Type I interferons (IFNs) represent a group of cytokines that act through a common receptor composed by two chains (IFNAR-1 and IFNAR-2). Several in vitro and in vivo studies showed a potent antitumor activity induced by these cytokines. IFN-α, the first cytokine to be produced by recombinant DNA technology, has emerged as an important regulator of cancer cell growth and differentiation, affecting cellular communication and signal transduction pathways. IFN-α, is currently the most used cytokine in the treatment of cancer. However, the potential anti-tumour activity of IFN-α is limited by the activation of tumour resistance mechanisms. This article reviews the current knowledge about the antitumor activity of type I IFNs, focusing on new potential strategies able to strengthen the antitumor activity of these cytokines.

Immune-modulating effects of the newest cetuximab-based chemoimmunotherapy regimen in advanced colorectal cancer patients.

Cetuximab is a human-murine chimeric monoclonal antibody to the epidermal growth factor receptor, active for advanced colorectal cancer treatment in combination with chemotherapy. Cetuximab mainly acts by inhibiting epidermal growth factor receptor-mediated pathways in cancer cells; however, in the human host, its IgG1 backbone may offer additional antitumor activity that includes FcγRs-mediated antibody-dependent cell cytotoxicity, phagocytosis, cross priming, and tumor-specific T-cell-mediated immune response. These mechanisms are still under active investigation. At this purpose, we have performed an immunologic investigation in advanced colon cancer patients enrolled in an ongoing phase II trial aimed to test the toxicity and the biological and antitumor activity of a novel biochemotherapy regimen combining polychemotherapy with gemcitabine, irinotecan, levofolinic acid, and fluorouracil with cetuximab and with subcutaneous low-dose metronomic aldesleukin (GILFICet regimen). The peripheral blood mononuclear cells of the first 20 patients enrolled in the GILFICet trial were collected at baseline and after 6 treatment cycles and examined for immune-phenotype change by flow cytometry. Colon cancer-specific T-cell lines were also generated ex vivo from these samples and subsequently characterized for immune phenotype, functional activity, and antigen specificity. We found a treatment-related increase of circulating dendritic cells, natural killer cells, central memory T cells, and activated T cells with a T-helper 1 (Th1)-cytotoxic phenotype. In addition, the ex-vivo characterization of antigen-specific T cells derived from the treated patients revealed a significant increase in proliferating cytotoxic T-lymphocyte precursors specific for carcinoembryonic antigen and thymidylate synthase derivative epitope peptides. On these basis, we concluded that the GILFICet regimen exerts substantial immune-modulating activity that significantly affects tumor antigen-specific T-cell compartment with potential antitumor activity.

Role of systemic chemotherapy in the management of resected or resectable colorectal liver metastases: a systematic review and meta-analysis of randomized controlled trials.

Liver metastases are a common event in patients with colorectal cancer. Surgical resection, if feasible, produces a survival benefit. We performed a systematic review of randomized clinical trials (RCT) and meta-analysis to address the question if current available studies support the use of systemic chemotherapy as an adjunct to surgery in resected/resectable patients. The search was based on major databases (Pubmed, CancerLit, Embase, Medscape and Cochrane) of published literature and selecting abstracts from major cancer meetings. We performed a literature for the January 1982-May 2010 time frame. The hazard ratios (HRs), with confidence intervals, as presented in retrieved studies, referred to the disease- and/or progression-free (DFS and/or PFS) and overall survival (OS) were extracted. The meta-analysis was carried out by the fixed-effect and the random-effects model. Three studies randomizing combined treatment vs. surgery alone for a total of 666 patients (642 evaluable for survival analysis) were selected and included in the final analysis. Evidence for chemotherapy-induced benefit in terms of both DFS (pooled HR, 0.71; CI, 0.582-0.878; p=0.001) and PFS (pooled HR, 0.75; CI, 0.620-0.910; p=0.003) was demonstrated. However, our meta-analysis failed to demonstrate a significant advantage of combined treatment in terms of OS (pooled HR, 0.743; CI, 0.527-1.045; p=0.088). Chemotherapy combined with surgical resection of colorectal liver metastases improves DFS and PFS whereas the benefit in OS is not demonstrated on the basis of the available results of RCTs. New prospective trials in the era of targeted therapy are eagerly awaited on this specific topic.

Tumour-specific uptake of anti-cancer drugs: the future is here.

A challenge of anti-cancer treatment is the specific delivery of the drugs in order to avoid deleterious effects on normal cells. In fact, anti-cancer drugs have potent effects also on normal cells due to the strong similarity of the mechanisms of growth regulation of normal cells if compared to their transformed counterparts. The recent developments in nanotechnology allow the old Ehrlich's dream to deliver anti-cancer drugs in tumour tissue through their encapsulation in drug delivery systems (DDS). In the present review we analyze the different reasons to encapsulate an anti-tumour drug in DDS including eventual damages induced by their extravasation or by eccipients used to their solubilisation, the rapid break-down of the drug in vivo and the specific bio-distribution of the drug in tumour tissues. The delivery strategies of anti-cancer drugs are based upon the particular structure of tumour neo-angiogenic vessels that allow the passive targeting or enhanced permeability and retention (EPR). In order to avoid the entrapping of DDS in reticulo-endothelial system the nanoparticles can be modified with the addition on their surface of inert polyetilenglicole (PEG) molecules that inhibit the opsonisation of DDS by macrophages. The addition of targeting moieties, antibodies or Fab fragments or small peptides and aptamers, on the surface of DDS can allow the active targeting of DDS to tumour cells. In conclusion, a new avenue in anti-cancer treatment has been disclosed with the use of DDS.

Nanotechnologies: a strategy to overcome blood-brain barrier.

The possibility to treat central nervous system (CNS) disorders is strongly limited by the poor access of many therapeutic agent to the target tissues. This is mainly due to the presence of the blood-brain barrier (BBB), formed by a complex interplay of endothelial cells, astrocyte and pericytes, through which only selected molecules can passively diffuse to reach CNS. Drug pharmacokinetics and biodistribution can be changed by using nanotechnology, in order to improve drug accumulation into the action site and to limit the drug release in the healthy tissues. When the CNS diseases are characterised by BBB altered permeability, an enhanced drug delivery into the brain can be achieved by using nanocarriers. Moreover, modification of nanocarrier surface with specific endogenous or exogenous ligands can promote enhanced BBB crossing, also in case of unaltered endothelium. This review summarizes the most meaningful advances in the field of nanotechnology for brain delivery of therapeutics.

New self-assembly nanoparticles and stealth liposomes for the delivery of zoledronic acid: a comparative study.

Zoledronic acid (ZOL) is a drug whose potent anti-cancer activity is limited by its short plasma half-life and rapid uptake and accumulation within bone. We have recently proposed new delivery systems to avoid ZOL accumulation into the bone, thus improving extra-skeletal bioavailability. In this work, we have compared the technological and anti-cancer features of either ZOL-containing self-assembly PEGylated nanoparticles (NPs) or ZOL-encapsulating PEGylated liposomes (LIPO-ZOL). ZOL-containing NPs showed superior technological characteristics in terms of mean diameter, size distribution, and ZOL encapsulation efficiency, compared to LIPO-ZOL. Moreover, the anti-cancer activity of NPs in nude mice xenografted with prostate cancer PC3 cells was higher than that one induced by LIPO-ZOL. In addition, NPs induced the complete remission of tumour xenografts and an increase of survival time higher than that one observed with LIPO-ZOL. It has also to be considered that PC3 tumour xenografts were almost completely resistant to the anti-cancer effects induced by free ZOL. Both nanotechnological products did not induce toxic effects not affecting the mice weight nor inducing deaths. Moreover, the histological examination of some vital organs such as liver, kidney and spleen did not find any changes in terms of necrotic effects or modifications in the inflammatory infiltrate. On the other hand, NPs but not LIPO-ZOL caused a statistically significant reduction of the tumour associated macrophages (TAM) in tumour xenografts. This effect was paralleled by a significant increase of both necrotic and apoptotic indexes. The effects of the NPs were also higher in terms of neo-angiogenesis inhibition. These results suggest the future preclinical development of ZOL-encapsulating NPs in the treatment of human cancer.

Core-shell biodegradable nanoassemblies for the passive targeting of docetaxel: features, antiproliferative activity and in vivo toxicity.

Amphiphilic block copolymers of poly(ɛ-caprolactone) and poly(ethylene oxide) were assembled in core-shell nanoparticles (NPs) by a melting-sonication technique (MeSo). The entrapment of the poorly water-soluble anticancer drug docetaxel (DTX), nanocarrier cytotoxicity toward different cells and toxicity in mice were investigated. The encapsulation mechanism was rationalized and related to copolymer properties such as crystallinity and drug solubility in the copolymer phase. DTX release from NPs occurred in 2 drug pulses over 30 days. DTX entrapment in NPs strongly decreased haemolysis of erythrocytes in comparison with a commercial DTX formulation. In comparison with free DTX, NPs were both more efficient in inhibiting cell growth of breast and prostate cancer cells and less toxic in experimental animal models. The results of this study indicate that MeSo is an interesting technique for the achievement of peculiar core-shell nanocarriers for the passive targeting and sustained release of poorly water-soluble anticancer drugs. FROM THE CLINICAL EDITOR: In this study, stealth nanoparticles of PEO/PCL block copolymers for passive targeting of docetaxel to solid tumors were developed using a novel technique. The studied properties of NPs suggest strong potential as anticancer drug-delivery system.

The PPAR-γ agonist troglitazone antagonizes survival pathways induced by STAT-3 in recombinant interferon-ß treated pancreatic cancer cells.

We have previously shown that cancer cells can protect themselves from apoptosis induced by type I interferons (IFNs) through a ras→MAPK-mediated pathway. In addition, since IFN-mediated signalling components STATs are controlled by PPAR gamma we studied the pharmacological interaction between recombinant IFN-ß and the PPAR-γ agonist troglitazone (TGZ). This combination induced a synergistic effect on the growth inhibition of BxPC-3, a pancreatic cancer cell line, through the counteraction of the IFN-ß-induced activation of STAT-3, MAPK and AKT and the increase in the binding of both STAT-1 related complexes and PPAR-γ with specific DNA responsive elements. The synergism on cell growth inhibition correlated with a cell cycle arrest in G0/G1 phase, secondary to a long-lasting increase of both p21 and p27 expressions. Blockade of MAPK activation and the effect on p21 and p27 expressions, induced by IFN-ß and TGZ combination, were due to the decreased activation of STAT-3 secondary to TGZ. IFN-ß alone also increased p21 and p27 expression through STAT-1 phosphorylation and this effect was attenuated by the concomitant activation of IFNbeta-induced STAT-3-activation. The combination induced also an increase in autophagy and a decrease in anti-autophagic bcl-2/beclin-1 complex formation. This effect was mediated by the inactivation of the AKT→mTOR-dependent pathway. To the best of our knowledge this is the first evidence that PPAR-γ activation can counteract STAT-3-dependent escape pathways to IFN-ß-induced growth inhibition through cell cycle perturbation and increased autophagic death in pancreatic cancer cells.

Role of endothelial nitric oxide synthase (eNOS) in chronic stress-promoted tumour growth.

Accumulating evidence suggests that chronic stress can be a cofactor for the initiation and progression of cancer. Here we evaluated the role of endothelial nitric oxide synthase (eNOS) in stress-promoted tumour growth of murine B16F10 melanoma cell line in C57BL/6 mice. Animals subjected to restraint stress showed increased levels adrenocorticotropic hormone, enlarged adrenal glands, reduced thymus weight and a 3.61-fold increase in tumour growth in respect to no-stressed animals. Tumour growth was significantly reduced in mice treated with the ß-antagonist propranolol. Tumour samples obtained from stressed mice displayed high levels of vascular endothelial growth factor (VEGF) protein in immunohistochemistry. Because VEGF can induce eNOS increase, and nitric oxide is a relevant factor in angiogenesis, we assessed the levels of eNOS protein by Western blot analysis. We found a significant increase in eNOS levels in tumour samples from stressed mice, indicating an involvement of this enzyme in stress-induced tumour growth. Accordingly, chronic stress did not promote tumour growth in eNOS(-/-) mice. These results disclose for the first time a pivotal role for eNOS in chronic stress-induced initiation and promotion of tumour growth.

Chondroitin sulphate enhances the antitumor activity of gemcitabine and mitomycin-C in bladder cancer cells with different mechanisms.

Non-muscle invasive bladder cancer is the most common type of bladder cancer in Western countries. The glycosaminoglycan (GAG) layer at the bladder surface non-specifically blocks the adherence of bacteria, ions and molecules to the bladder epithelium and bladder cancer cells express CD44 that binds GAG. Currently, there are few options other than cystectomy for the management of non-muscle invasive bladder cancer with intravesical chemotherapy using several drugs such as gemcitabine (GEM) and mitomycin-C (MMC) with poor prophylactic activity. In this study, we investigated the effects of the GAG chondroitin sulphate (CS) on the growth inhibition of human bladder cancer cell lines HT-1376 and effects of the combination between GEM or MMC with CS. We have found that CS, MMC and GEM induced 50% growth inhibition at 72 h. Therefore, we have evaluated the growth inhibition induced by different concentration of CS in combination with MMC or GEM, respectively, at 72 h. We have observed, at Calcusyn analysis, a synergism when HT-1376 cells were treated with CS in combination with MMC or GEM, respectively, if used at an equimolar ratio. We have also found that CS/GEM combination induced a strong potentiation of apoptosis with the consequent activation of caspases 9 and 3. On the other hand, HT-1376 cells were necrotic if exposed to the CS/MMC combination and no signs of caspase activation was observed. In conclusion, in the human bladder cancer cell line HT-1376 pharmacological combination of CS with GEM or MMC resulted in a strong synergism on cell growth inhibition.

Molecular targets and oxidative stress biomarkers in hepatocellular carcinoma: an overview.

Hepatocellular carcinoma (HCC) is a complex and heterogeneous tumor with multiple genetic aberrations. Several molecular pathways involved in the regulation of proliferation and cell death are implicated in the hepatocarcinogenesis. The major etiological factors for HCC are both hepatitis B virus (HBV) and hepatitis C virus infection (HCV). Continuous oxidative stress, which results from the generation of reactive oxygen species (ROS) by environmental factors or cellular mitochondrial dysfunction, has recently been associated with hepatocarcinogenesis. On the other hand, a distinctive pathological hallmark of HCC is a dramatic down-regulation of oxido-reductive enzymes that constitute the most important free radical scavenger systems represented by catalase, superoxide dismutase and glutathione peroxidase. The multikinase inhibitor sorafenib represents the most promising target agent that has undergone extensive investigation up to phase III clinical trials in patients with advanced HCC. The combination with other target-based agents could potentiate the clinical benefits obtained by sorafenib alone. In fact, a phase II multicenter study has demonstrated that the combination between sorafenib and octreotide LAR (So.LAR protocol) was active and well tolerated in advanced HCC patients. The detection of molecular factors predictive of response to anti-cancer agents such as sorafenib and the identification of mechanisms of resistance to anti-cancer agents may probably represent the direction to improve the treatment of HCC.

Epigenetic fingerprint in endometrial carcinogenesis: the hypothesis of a uterine field cancerization.

Transcriptional silencing by CpG island hypermethylation plays a critical role in endometrial carcinogenesis. In a collection of benign, premalignant and malignant endometrial lesions, a methylation profile of a complete gene panel, such steroid receptors (ERα, PR), DNA mismatch repair (hMLH1), tumor-suppressor genes (CDKN2A/P16 and CDH1/E-CADHERIN) and WNT pathway inhibitors (SFRP1, SFRP2, SFRP4, SFRP5) was investigated in order to demonstrate their pathogenetic role in endometrial lesions. Our results indicate that gene hypermethylation may be an early event in endometrial endometrioid tumorigenesis. Particularly, ERα, PR, hMLH1, CDKN2A/P16, SFRP1, SFRP2 and SFRP5 revealed a promoter methylation status in endometrioid carcinoma, whereas SFRP4 showed demethylation in cancer. P53 immunostaining showed weak-focal protein expression level both in hyperplasic lesions and in endometrioid cancer. Non-endometrioid cancers showed very low levels of epigenetic methylations, but strong P53 protein positivity. Fisher exact test revealed a statistically significant association between hMLH1, CDKN2A/P16 and SFRP1 genes methylation and endometrioid carcinomas and between hMLH1 gene methylation and peritumoral endometrium (p < 0.05). Our data confirm that the methylation profile of the peritumoral endometrium is different from the altered molecular background of benign endometrial polyps and hyperplasias. Therefore, our findings suggest that the methylation of hMLH1, CDKN2A/P16 and SFRP1 may clearly distinguish between benign and malignant lesions. Finally, this study assessed that the use of an epigenetic fingerprint may improve the current diagnostic tools for a better clinical management of endometrial lesions.

Analysis of interaction partners for eukaryotic translation elongation factor 1A M-domain by functional proteomics.

The eukaryotic translation elongation factor 1A (eEF1A), besides to its canonical role in protein synthesis, is also involved in several other cellular processes, depending on changes in cellular location, cell type, concentration of ligands, substrates or cofactors. Therefore eEF1A is a moonlighting protein that participates to a network of molecular interactions involving its structural domains. Since the identification of novel protein-protein interactions represents important tasks in post-genomic era, the interactome of eEF1A1 M-domain was investigated by using a proteomic approach. To this purpose, the eEF1A1 M-domain was fused with glutathione-S-transferase (GST) and Strep-tag (ST) at it's N- and C-terminal, respectively. The recombinant protein (GST-M-ST) was purified and incubated with a mouse embryo lysate by applying an affinity chromatography strategy. The interacting proteins were separated by SDS-PAGE and identified by peptide mass fingerprinting using MALDI-TOF mass spectrometry. Besides the known partners, the pool of interacting proteins contained sorbin, a polypeptide of 153 amino acids present in SH3 domain-containing adaptor proteins, such as SORBS2. This interaction was also assessed by Western blot on immunoprecipitate from mouse embryo or H1355 cell lysates with anti-eEF1A or anti-SORBS2 antibodies and on eEF1A1-His pull-down from H1355 cell lysate with antibody anti-SORBS2. Furthermore, the interaction between eEF1A and SORBS2 was also confirmed by confocal microscopy and FRET analysis. Interestingly, a co-localization of SORBS2 and eEF1A was evidenced at level of plasma membrane, thus suggesting the involvement of eEF1A1 in novel key signal transduction complexes.

The role of tissue microarray in the era of target-based agents.

Tissue microarray (TMA) technologies have been developed over the last years, mainly to identify biomarkers useful for the correct identification and characterization of tumors. Moreover, TMA has been implemented in retrospective studies in order to identify predictive biomarkers of response to a given therapy and/or to find potential new targets for biological therapy. We analyzed the fields of application of TMA technology and the design of TMA varying according to the objectives to be studied. In this article, the reader will learn how to design TMAs in order to cover the objectives of clinical trials based upon the use of target-based agents. The main limits and advantages of TMA and the results achieved in cancer diagnosis will be also described. Tissue microarray technology should be systematically applied to define critical markers, in retrospective studies and in the screening of most human tumors in order to find new possible molecular targets and to molecularly define the diagnosis of the neoplastic diseases. TMAs have substantially improved the field of translational studies, even in the design and follow-up of studies based upon the use of target-based agents in cancer therapy.

Nanotechnologies to use bisphosphonates as potent anticancer agents: the effects of zoledronic acid encapsulated into liposomes.

Zoledronic acid (ZOL) is a potent amino-bisphosphonate used for the treatment of bone metastases with recently reported antitumor activity. However, the short plasma half-life and rapid accumulation in bone limits the use of ZOL as an antitumor agent in extraskeletal tissues. Therefore, we developed stealth liposomes encapsulating ZOL (LipoZOL) to increase extraskeletal drug availability. Compared to free ZOL, LipoZOL induced a stronger inhibition of growth of a range of different cancer cell lines in vitro. LipoZOL also caused significantly larger inhibition of tumor growth and increased the overall survival in murine models of human prostate cancer and multiple myeloma, in comparison with ZOL. Moreover, a strong inhibition of vasculogenetic events without evidence of necrosis in the tumor xenografts from prostate cancer was recorded after treatment with LipoZOL. We demonstrated both antitumor activity and tolerability of LipoZOL in preclinical animal models of both solid and hematopoietic malignancies, providing a rationale for early exploration of use of LipoZOL as a potential anticancer agent in cancer patients. FROM THE CLINICAL EDITOR: The short plasma half-life and rapid accumulation in bone limits the use of zoledronic acid as an antitumor agent in extraskeletal tissues. Therefore, stealth liposomes encapsulating ZOL (LipoZOL) have been developed to increase extraskeletal drug availability.

Phase II trial of bevacizumab and dose/dense chemotherapy with cisplatin and metronomic daily oral etoposide in advanced non-small-cell-lung cancer patients.

Bevacizumab, is a humanized monoclonal antibody to vasculo-endothelial-growth-factor, with anticancer activity in non-small-cell-lung cancer (NSCLC) patients. Our previous results from a dose/finding phase I trial in NSCLC patients, demonstrated the anti-angiogenic effects and toxicity of a newest bevacizumab-based combination with fractioned cisplatin and daily oral etoposide. We designed a phase II trial to evaluate in advanced NSCLC patients the antitumor activity and the safety of this novel regimen. In particular, 45 patients (36 males and 9 females), with a mean age of 54 years, an ECOG ≤ 2, stage IIIB/IV and NSCLC (28 adenocarcinomas, 11 squamous-cell carcinomas, 2 large-cell carcinomas, 4 undifferentiated carcinomas), were enrolled. They received cisplatin (30 mg/sqm, days 1-3), oral etoposide (50 mg, days 1-15) and bevacizumab (5 mg/kg, day 3) every three weeks (mPEBev regimen). Patients who achieved an objective response or stable disease received maintenance treatment with bevacizumab in combination with erlotinib until progression. Grade I-II hematological, mucosal toxicity and alopecia were the most common adverse events. The occurrence of infections (17%), thromboembolic events (4.4%) and severe mood depression (6.7%) was also recorded. A partial response was achieved in 31 (68.8%) patients, disease remained stable in 8 (17.8%), and disease progressed in 6 (13.3%) with a progression-free-survival of 9.53 months (95%CI, 7.7-11.46). Our bio-chemotherapy regimen resulted very active in advanced NSCLC, however, the toxicity associated with the treatment requires strict selection of the patients to enroll in future studies.