Carboplatin-paclitaxel compared to Carboplatin-Paclitaxel-Bevacizumab in advanced or recurrent endometrial cancer: MITO END-2 - A randomized phase II trial.

OBJECTIVE: Increased Vascular Endothelial Growth Factor Receptor (VEGF) expression in endometrial cancer (EC) is associated with a poor prognosis. Preliminary clinical data reported Bevacizumab effectiveness in EC both as single agent and in combination with chemotherapy. METHODS: In a phase II trial, patients with advanced (FIGO stage III-IV) or recurrent EC were randomized to receive Carboplatin-Paclitaxel standard dose for 6-8 cycles vs Carboplatin-Paclitaxel and Bevacizumab 15 mg/kg in combination with chemotherapy and maintenance until disease progression or unacceptable toxicity. The primary endpoint was progression free survival (PFS). RESULTS: 108 patients were randomized; PFS (10.5 vs 13.7 months, HR 0.84 p = 0.43), overall response rate (ORR 53.1% vs 74.4%) and overall survival (OS) (29.7 vs 40.0 months, HR 0.71 p = 0.24) resulted in a non-significant increase in Bevacizumab treated patients. The PFS increase became significant when an exploratory analysis with the Breslow test was used. Moreover, patients treated with Bevacizumab experienced a significant increase in 6-month disease control rate (70.4% vs 90.7%). Cardiovascular events were more frequent in the experimental arm ("de novo" grade ≥2 hypertension 21% vs 0% and grade ≥2 thromboembolic events 11% vs 2% in the Bevacizumab vs standard treatment arm, respectively). CONCLUSIONS: Bevacizumab combined with chemotherapy in the treatment of advanced/recurrent EC failed to demonstrate a significant increase in PFS in the MITO END-2 trial. Nevertheless, these preliminary data suggests some effectiveness of the antiangiogenic agent which merits further exploration in a larger population with a better molecular characterization.

Systemic therapy treatment patterns in patients with advanced non-small cell lung cancer (NSCLC): PIvOTAL study.

The aim of this multinational retrospective cohort study, conducted at academic and community oncology centres, was to describe real-world treatment patterns for patients with a confirmed diagnosis of advanced/metastatic (stage IIIB/IV) non-small cell lung cancer (NSCLC) who initiated first-line systemic therapy from January 2011 through June 2014. The study included 1265 patients in Italy, Spain, Germany, Australia, Korea, Taiwan and Brazil. The proportion of patients with squamous versus non-squamous NSCLC was approximately 20% versus 75%, and associated patient demographic characteristics were similar in all countries, excepting race. Patients with squamous NSCLC were predominantly male and current/ex-smokers. Biomarker tests were performed for the majority of patients with non-squamous NSCLC, ranging from 54% (Brazil) to 91% in Taiwan, where, of those tested, 68% with non-squamous NSCLC had positive epidermal growth factor receptor (EGFR)-mutation status; in other countries the EGFR-positive percentages ranged from 17% (Spain/Brazil) to 40% (Korea). Platinum-based regimens were the most common first-line therapy in all countries except Taiwan, where gefitinib was the most common first-line agent. Median overall survival ranged from 9.3 months (Brazil) to 25.5 months (Taiwan). The diagnostic and treatment patterns recorded in this study were heterogeneous but largely in line with NSCLC guidelines during the study period.

Cetuximab ± chemotherapy enhances dendritic cell-mediated phagocytosis of colon cancer cells and ignites a highly efficient colon cancer antigen-specific cytotoxic T-cell response in vitro.

Cetuximab is a human/mouse chimeric IgG1 monoclonal antibody (mAb) to epidermal growth factor receptor, approved for colorectal carcinoma treatment in combination with chemotherapy. The immune-mediated effects elicited by its human fraction of crystallization moiety might critically contribute to the overall anti-tumor effectiveness of the antibody. We therefore investigated cetuximab ability to promote colon cancer cell opsonization and phagocytosis by human dendritic cells (DCs) that are subsequently engaged in antigen-cross presentation to cytotoxic T-lymphocyte (CTL) precursors. Human colon cancer cell lines were evaluated for susceptibility to DC-mediated phagocytosis before and after treatment with chemotherapy ± cetuximab in vitro. Human DCs loaded with control or drug-treated cetuximab-coated colon cancer cells were used to in vitro generate cytotoxic T cell clones from peripheral blood mononuclear cells of human leucocyte antigen-A(*)02.01(+) donors. T-cell cultures were characterized for immune-phenotype and tumor-antigen specific CTL activity. The results confirmed that treatment of tumor cells with irinotecan + L-folinate + 5-flurouracil (ILF) or with gemcitabine + ILF increased tumor antigen expression. Moreover, malignant cells exposed to chemotherapy and cetuximab were highly susceptible to phagocytosis by human DCs and were able to promote their activation. The consequent DC-mediated cross-priming of antigens derived from mAb-covered/drug-treated cancer cells elicited a robust CTL anti-tumor response. On the basis of our data, we suggest a possible involvement of CTL-dependent immunity in cetuximab anti-cancer effects.

Efficacy and safety of first-line checkpoint inhibitors-based treatments for non-oncogene-addicted non-small-cell lung cancer: a systematic review and meta-analysis.

BACKGROUND: Frontline immune checkpoint inhibitors (ICI)-based regimens in non-oncogene-addicted non-small-cell lung cancer (NSCLC) have been deeply investigated. To rank the available therapeutic options, we carried out a systematic review and Bayesian meta-analysis. METHODS: A comprehensive search for randomized controlled trials (RCTs) of ICI regimens, and a pairwise and a network meta-analysis (NMA) with an all-comers and a stratified strategy were conducted. Endpoints were overall survival (OS), progression-free survival (PFS), objective response rate (ORR) and treatment-related adverse events (TRAEs). RESULTS: Nineteen RCTs involving 17 treatment regimens were included. For the all-comers population, pembrolizumab/chemotherapy (CT) and cemiplimab were most likely the best treatments. For programmed death-ligand 1 (PD-L1) <1% nivolumab/ipilimumab with/without CT, for PD-L1 >1% and 1%-49% pembrolizumab/CT and for PD-L1 >50% cemiplimab ranked first for OS. In non-squamous (NSQ), pembrolizumab with/without CT ranked first for OS; cemiplimab ranked worse than the unselected population. In squamous (SQ), pooled hazard ratio (HR) showed a better chance in improving efficacy for combination strategy, while monotherapy did not, except for cemiplimab that ranked second. Atezolizumab/CT/bevacizumab ranked first in most subgroups for PFS. Direct comparison showed a non-statistically significant benefit of ICI regimens for the liver metastases cohort in OS, with a good ranking for pembrolizumab/CT and atezolizumab/bevacizumab/CT. Regarding brain metastases, all ICI regimens demonstrated an improvement in OS and PFS compared to CT. Nivolumab/ipilimumab/CT ranked better in this subset. CONCLUSIONS: Our meta-analysis updated on the most recent findings demonstrates that different ICI treatments rank differently in specific NSCLC settings (histology, biomarker and clinical presentation) offering a novel challenging scenario for clinical decision making and research planning.

Implementation of preventive and predictive BRCA testing in patients with breast, ovarian, pancreatic, and prostate cancer: a position paper of Italian Scientific Societies.

Constitutional BRCA1/BRCA2 pathogenic or likely pathogenic variants (PVs) are associated with an increased risk for developing breast and ovarian cancers. Current evidence indicates that BRCA1/2 PVs are also associated with pancreatic cancer, and that BRCA2 PVs are associated with prostate cancer risk. The identification of carriers of constitutional PVs in the BRCA1/2 genes allows the implementation of individual and family prevention pathways, through validated screening programs and risk-reducing strategies. According to the relevant and increasing therapeutic predictive implications, the inclusion of BRCA testing in the routine management of patients with breast, ovarian, pancreatic and prostate cancers represent a key requirement to optimize medical or surgical therapeutic and prevention decision-making, and access to specific anticancer therapies. Therefore, accurate patient selection, the use of standardized and harmonized procedures, and adherence to homogeneous testing criteria, are essential elements to implement BRCA testing in clinical practice. This consensus position paper has been developed and approved by a multidisciplinary Expert Panel of 64 professionals on behalf of the AIOM-AIRO-AISP-ANISC-AURO-Fondazione AIOM-SIAPEC/IAP-SIBioC-SICO-SIF-SIGE-SIGU-SIU-SIURO-UROP Italian Scientific Societies, and a patient association (aBRCAdaBRA Onlus). The working group included medical, surgical and radiation oncologists, medical and molecular geneticists, clinical molecular biologists, surgical and molecular pathologists, organ specialists such as gynecologists, gastroenterologists and urologists, and pharmacologists. The manuscript is based on the expert consensus and reports the best available evidence, according to the current eligibility criteria for BRCA testing and counseling, it also harmonizes with current Italian National Guidelines and Clinical Recommendations.

The molecular profiling of solid tumors by liquid biopsy: a position paper of the AIOM-SIAPEC-IAP-SIBioC-SIC-SIF Italian Scientific Societies.

The term liquid biopsy (LB) refers to the use of various biological fluids as a surrogate for neoplastic tissue to achieve information for diagnostic, prognostic and predictive purposes. In the current clinical practice, LB is used for the identification of driver mutations in circulating tumor DNA derived from both tumor tissue and circulating neoplastic cells. As suggested by a growing body of evidence, however, there are several clinical settings where biological samples other than tissue could be used in the routine practice to identify potentially predictive biomarkers of either response or resistance to targeted treatments. New applications are emerging as useful clinical tools, and other blood derivatives, such as circulating tumor cells, circulating tumor RNA, microRNAs, platelets, extracellular vesicles, as well as other biofluids such as urine and cerebrospinal fluid, may be adopted in the near future. Despite the evident advantages compared with tissue biopsy, LB still presents some limitations due to both biological and technological issues. In this context, the absence of harmonized procedures corresponds to an unmet clinical need, ultimately affecting the rapid implementation of LB in clinical practice. In this position paper, based on experts' opinions, the AIOM-SIAPEC-IAP-SIBIOC-SIF Italian Scientific Societies critically discuss the most relevant technical issues of LB, the current and emerging evidences, with the aim to optimizing the applications of LB in the clinical setting.

C-Raf antagonizes apoptosis induced by IFN-alpha in human lung cancer cells by phosphorylation and increase of the intracellular content of elongation factor 1A.

Interferon alpha (IFNalpha) induces both apoptosis and a counteracting epidermal growth factor Erk-dependent survival response in cancer cells. In this report, IFNalpha increased eukaryotic elongation factor 1A (eEF-1A) protein expression by inhibition of eEF-1A degradation via a proteasome-dependent pathway. The reduction of the expression level of eEF-1A by RNA interference enhanced the apoptosis induced by IFNalpha on the same cells. Moreover, IFNalpha induced the phosphorylation of both serine and threonine in eEF-1A. These effects were paralleled by an increased co-immunoprecipitation and colocalization of eEF-1A with C-Raf. The suppression of C-Raf kinase activity with the inhibitor BAY 43-9006 completely antagonized the increase of both eEF-1A phosphorylation and expression and of C-Raf/eEF-1A colocalization induced by IFNalpha and enhanced apoptosis and eEF-1A ubiquitination. Cell transfection with the mutated K48R ubiquitin increased EF-1A expression and desensitized tumor cells to the modulating effects of IFNalpha. The dynamic simulation of 3Dstructure of eEF-1A identified putative serine and threonine phosphorylation sites. In conclusion, the interaction between eEF-1A and C-Raf increases eEF-1A stability and induces a survival activity.

Protein arginine methyltransferase 5 has prognostic relevance and is a druggable target in multiple myeloma.

Arginine methyltransferases critically regulate cellular homeostasis by modulating the functional outcome of their substrates. The protein arginine methyltransferase 5 (PRMT5) is an enzyme involved in growth and survival pathways promoting tumorigenesis. However, little is known about the biologic function of PRMT5 and its therapeutic potential in multiple myeloma (MM). In the present study, we identified and validated PRMT5 as a new therapeutic target in MM. PRMT5 is overexpressed in patient MM cells and associated with decreased progression-free survival and overall survival. Either genetic knockdown or pharmacological inhibition of PRMT5 with the inhibitor EPZ015666 significantly inhibited growth of both cell lines and patient MM cells. Furthermore, PRMT5 inhibition abrogated NF-κB signaling. Interestingly, mass spectrometry identified a tripartite motif-containing protein 21 TRIM21 as a new PRMT5-partner, and we delineated a TRIM21-dependent mechanism of NF-κB inhibition. Importantly, oral administration of EPZ015666 significantly decreased MM growth in a humanized murine model of MM. These data both demonstrate the oncogenic role and prognostic relevance of PRMT5 in MM pathogenesis, and provide the rationale for novel therapies targeting PRMT5 to improve patient outcome.

MiR-29b antagonizes the pro-inflammatory tumor-promoting activity of multiple myeloma-educated dendritic cells.

Dendritic cells (DCs) have a key role in regulating tumor immunity, tumor cell growth and drug resistance. We hypothesized that multiple myeloma (MM) cells might recruit and reprogram DCs to a tumor-permissive phenotype by changes within their microRNA (miRNA) network. By analyzing six different miRNA-profiling data sets, miR-29b was identified as the only miRNA upregulated in normal mature DCs and significantly downregulated in tumor-associated DCs. This finding was validated in primary DCs co-cultured in vitro with MM cell lines and in primary bone marrow DCs from MM patients. In DCs co-cultured with MM cells, enforced expression of miR-29b counteracted pro-inflammatory pathways, including signal transducer and activator of transcription 3 and nuclear factor-κB, and cytokine/chemokine signaling networks, which correlated with patients' adverse prognosis and development of bone disease. Moreover, miR-29b downregulated interleukin-23 in vitro and in the SCID-synth-hu in vivo model, and antagonized a Th17 inflammatory response. All together, these effects translated into strong anti-proliferative activity and reduction of genomic instability of MM cells. Our study demonstrates that MM reprograms the DCs functional phenotype by downregulating miR-29b whose reconstitution impairs DCs ability to sustain MM cell growth and survival. These results underscore miR-29b as an innovative and attractive candidate for miRNA-based immune therapy of MM.

Targeting Raf-kinase: molecular rationales and translational issues.

Target-based therapy has been a promising anti-cancer strategy in the preclinical setting, but its efficacy is still limited in clinical practice. The latter was probably due to the lack of identification of molecular targets in order to predict clinical response and for the existence of multiple survival compensatory downstream pathways. Therefore, the use of downstream targets could be useful in order to avoid these overcoming pathways. One of these targets is Raf-kinase. In this review we describe the structure and functions of the components of Raf-kinase family and their relevance in proliferation and survival of tumor cells. Moreover, we illustrate the signal transduction pathways regulated by Raf-kinases. The main preclinical and clinical results obtained with the use of the Raf-kinase inhibitor BAY 43-9006 or sorafenib are also described. The multi-target function of sorafenib is also explained and the disclosure of new therapeutic opportunities based on the dual inhibition of cancer proliferation and neo-angiogenesis is discussed. In conclusion, Raf-kinase appears an appealing therapeutic target, even it other preclinical and clinical studies are warranted in order to evaluate the activity of sorafenib both in monotherapy and in combination with other agents.

Synergistic inhibition of growth of breast and colon human cancer cell lines by site-selective cyclic AMP analogues.

Our past studies on the mechanism of cyclic AMP (cAMP)-mediated control of tumor growth, using the experimental rat mammary tumor models as well as human breast cancer cell lines, indicated that the action of cAMP is mediated by the RII cAMP receptor protein, the regulatory subunit of cAMP-dependent protein kinase type II (Y. S. Cho-Chung, J. Cyclic Nucleotide Res., 6: 163, 1980). We now shown that the site-selective cAMP analogues, which are manyfold more active in binding to the cAMP receptor protein than previously studied analogues, demonstrate a potent growth inhibition of seven breast and three colon human cancer cell lines. The cAMP receptor protein has two different cAMP binding sites, and cAMP analogues that selectively bind to either one of the two binding sites are known as either site 1 selective (C-8 analogues) or site 2 selective (C-6 analogues). Nineteen site-selective analogues, C-6 and C-8 monosubstituted and C-6,-8 disubstituted, were tested for their growth regulatory effect. The majority of these analogues demonstrated an appreciable growth inhibition, with no sign of toxicity in all 10 cancer lines at micromolar concentrations. The three most potent inhibitors were 8-Cl-, N6-benzyl-, and N6-phenyl-8-thio-p-chlorophenyl-cAMP, demonstrating 50% growth inhibition at 5-25 microM concentrations (IC50). Furthermore, N6-analogues, in combination with halogen or thio derivatives of C-8 analogues, demonstrated synergistic enhancement of growth inhibition. The growth inhibition paralleled a change in cell morphology, an augmentation of the RII cAMP receptor protein, and a reduction in p21 ras protein. The growth inhibition by 8-Cl-cAMP was not due to its metabolite, 8-Cl-adenosine, since: (a) the growth inhibition by 8-Cl-cAMP was released upon cessation of treatment, whereas that by 8-Cl-adenosine was not released; (b) 8-Cl-cAMP treatment did not affect cell cycle progression, whereas 8-Cl-adenosine brought about G1 synchronization; (c) 8-Cl-cAMP treatment caused reduction of p21 ras protein, whereas 8-Cl-adenosine did not affect p21 levels; and (d) 8-Cl-adenosine was not detected in either cell extracts or medium from the cells treated with 8-Cl-cAMP for 48-72 h. Site-selective cAMP analogues thus provide a new physiological means to control the growth of breast and colon human cancer cells.

Reversal of adriamycin resistance by recombinant alpha-interferon in multidrug-resistant human colon carcinoma LoVo-doxorubicin cells.

Reversal of the drug resistance phenotype by the use of agents which induce cell differentiation offers an experimental approach to the study of chemoresistance. In numerous in vitro models, alpha-interferon (alpha-IFN) has been shown to induce phenotypical changes and to modulate the growth of cancer cells. The aim of the present study was to define the effect of alpha-IFN on the Adriamycin sensitivity of the human colon adenocarcinoma cell line, LoVo, and its Adriamycin-resistant variant, LoVo/DX. Pretreatment of LoVo/DX cells with 500 units/ml of alpha-IFN increased sensitivity to low doses of Adriamycin. Similar treatment conditions did not change the sensitivity of the parental cell line. Following treatment of the LoVo/DX cells with alpha-IFN plus 100 ng/ml Adriamycin for 1 h, 30% of the cells survived compared to 100% of untreated cells. This effect was not related to changes in cell cycle kinetics induced by alpha-IFN treatment and did not result from variations in the expression of P-glycoprotein at the cell surface, as assessed by flow cytometric analysis using monoclonal antibody MRK16. Adriamycin accumulation was increased by alpha-IFN as assessed by spectrofluorometric analysis. Thus, the data suggest that in LoVo/DX cells, alpha-IFN increased Adriamycin cytotoxicity through modulation of the multidrug resistance phenotype.

Upregulation of epidermal growth factor receptor induced by alpha-interferon in human epidermoid cancer cells.

Unregulated or increased expression of epidermal growth factor receptor (EGF-R) is a common event in neoplastic transformation; modulation of such a receptor by physiological agents could be, therefore, of clinical interest. We have studied the binding ability, the availability at cell surface, and the synthesis of EGF-R in the A431 and KB human epidermoid cancer cell lines after treatment with recombinant alpha-interferon (IFN-alpha). After 48 h of treatment, IFN-alpha induces, in both cell lines, growth inhibition and enhances class I major histocompatibility HLA complex expression, which is a common marker of IFN action. [125I]EGF total binding assessed after 48 h of treatment with IFN-alpha shows a dose-dependent upregulation of EGF-R binding capacity. Saturation plots of the binding data show that IFN-alpha treatment does not dramatically alter the affinity of the EGF-R and indicate that IFN-alpha only increases the number of low affinity receptors. We show that this effect is due to a specific increase in the synthesis of the receptor protein, as assessed by immunoprecipitation of [35S]methionine-labeled cell extracts. Electron microscopy analysis has confirmed an increase of EGF-R proteins at cell surface without major changes in the morphology of the cells. Taken together, these results indicate that IFN-alpha consistently induces both the binding capacity and the synthesis of EGF-R in human epidermoid cancer cells and suggest the use of such a mechanism for new anticancer therapies.

A gene expression inflammatory signature specifically predicts multiple myeloma evolution and patients survival.

Multiple myeloma (MM) is closely dependent on cross-talk between malignant plasma cells and cellular components of the inflammatory/immunosuppressive bone marrow milieu, which promotes disease progression, drug resistance, neo-angiogenesis, bone destruction and immune-impairment. We investigated the relevance of inflammatory genes in predicting disease evolution and patient survival. A bioinformatics study by Ingenuity Pathway Analysis on gene expression profiling dataset of monoclonal gammopathy of undetermined significance, smoldering and symptomatic-MM, identified inflammatory and cytokine/chemokine pathways as the most progressively affected during disease evolution. We then selected 20 candidate genes involved in B-cell inflammation and we investigated their role in predicting clinical outcome, through univariate and multivariate analyses (log-rank test, logistic regression and Cox-regression model). We defined an 8-genes signature (IL8, IL10, IL17A, CCL3, CCL5, VEGFA, EBI3 and NOS2) identifying each condition (MGUS/smoldering/symptomatic-MM) with 84% accuracy. Moreover, six genes (IFNG, IL2, LTA, CCL2, VEGFA, CCL3) were found independently correlated with patients' survival. Patients whose MM cells expressed high levels of Th1 cytokines (IFNG/LTA/IL2/CCL2) and low levels of CCL3 and VEGFA, experienced the longest survival. On these six genes, we built a prognostic risk score that was validated in three additional independent datasets. In this study, we provide proof-of-concept that inflammation has a critical role in MM patient progression and survival. The inflammatory-gene prognostic signature validated in different datasets clearly indicates novel opportunities for personalized anti-MM treatment.

Immune-modulating effects of bevacizumab in metastatic non-small-cell lung cancer patients.

The mPEBev is an anticancer regimen which combines a chemotherapy doublet, based on cisplatin and oral etoposide (mPE), with bevacizumab (mPEBev), a mAb targeting the vasculo-endothelial growth factor (VEGF). In previous studies, this regimen showed powerful anti-angiogenetic effects and significant antitumor activity in metastatic non-small-cell lung cancer (mNSCLC) patients. We also recorded the best benefit in patients exhibiting low-systemic inflammatory profile at baseline. On these bases, we hypothesized that mPEBev antitumor activity could be partially related to bevacizumab-associated immunological effects. For this reason, we performed an immunological monitoring in 59 out of 120 stage IIIb-IV NSCLC patients enrolled in the BEVA2007 phase II trial, who received fractioned cisplatin (30 mg/sqm days 1-3q21) and oral etoposide (50 mg, days 1-15q21) (mPE doublet) ±bevacizumab. In this group of patients, 12 received the mPE doublet alone and 47 the doublet in combination with bevacizumab (5 mg/kg on the day 3q21; mPEBev regimen). Blood cell counts, serum analysis, multiplex cytokine assay and immunocytofluorimetric analysis, performed on baseline and post-treatment on blood samples from these patients, revealed that bevacizumab addition to the doublet decreased levels of pro-angiogenic (VEGF, Angiostatin-1 and Follistatin) and inflammatory cytokines (interferon (IFN)γ, IL4 and IL17), improved in vivo and in vitro cytotoxic T-lymphocytes (CTL) response and promoted dendritic cell activation. These results suggest that the mPEBev regimen improve the micro-environmental conditions for an efficient antigen-specific CTL response, making it a feasible candidate regimen to be assessed in combination with immune-checkpoint inhibitors in NSCLC patients.

EGF activates an inducible survival response via the RAS-> Erk-1/2 pathway to counteract interferon-alpha-mediated apoptosis in epidermoid cancer cells.

The mechanisms of tumor cell resistance to interferon-alpha (IFNalpha) are at present mostly unsolved. We have previously demonstrated that IFNalpha induces apoptosis on epidermoid cancer cells and EGF antagonizes this effect. We have also found that IFNalpha-induced apoptosis depends upon activation of the NH(2)-terminal Jun kinase-1 (Jnk-1) and p(38) mitogen-activated protein kinase, and that these effects are also antagonized by EGF. At the same time, IFNalpha increases the expression and function of the epidermal growth factor receptor (EGF-R). Here we report that the apoptosis induced by IFNalpha occurs together with activation of caspases 3, 6 and 8 and that EGF also antagonizes this effect. On the basis of these results, we have hypothesized that the increased EGF-R expression and function could represent an inducible survival response that might protect tumor cells from apoptosis caused by IFNalpha via extracellular signal regulated kinase 1 and 2 (Erk-1/2) cascades. We have found an increased activity of Ras and Raf-1 in IFNalpha-treated cells. Moreover, IFNalpha induces a 50% increase of the phosphorylated isoforms and enzymatic activity of Erk-1/2. We have also demonstrated that the inhibition of Ras activity induced by the transfection of the dominant negative Ras plasmid RASN17 and the inhibition of Mek-1 with PD098059 strongly potentiates the apoptosis induced by IFNalpha. Moreover, the selective inhibition of this pathway abrogates the counteracting effect of EGF on the IFNalpha-induced apoptosis. All these findings suggest that epidermoid tumor cells counteract the IFNalpha-induced apoptosis through a survival pathway that involves the hyperactivation of the EGF-dependent Ras->Erk signalling. The selective targeting of this pathway appears to be a promising approach in order to enhance the antitumor activity of IFNalpha.

Interferon-alpha induces apoptosis in human KB cells through a stress-dependent mitogen activated protein kinase pathway that is antagonized by epidermal growth factor.

We have demonstrated that interferon-alpha2-recombinant (IFNalpha) at growth inhibitory concentrations enhances the expression and signalling activity of the epidermal growth factor receptor (EGF-R) in human epidermoid carcinoma KB cells. Here we report that KB cells exposed to IFNalpha underwent apoptotic cell death and this effect was antagonized by EGF. We have also found that IFNalpha enhanced the expression of heat shock proteins (HSP) HSP-70, HSP-90 and HSP-27 and activated the NH2-terminal Jun kinase-1 (JNK-1) and p38 mitogen activated protein kinase, the target enzymes of a stress-dependent intracellular transduction pathway. Moreover, the overexpression of the wild-type JNK-1, obtained through plasmid transfection of KB cells, induced apoptosis which was potentiated by the exposure of wild-type JNK-1 (JNK-1wt)-transfected cells to IFNalpha. All these effects were neutralized by the addition of EGF to parental and JNK-1wt-transfected KB cells exposed to IFNalpha. In conclusion, EGF has a protective effect on KB cells from apoptosis while antagonizing a stress response elicited by IFNalpha and targeted on the stress pathway terminal kinases.

Antitumor therapeutic strategies based on the targeting of epidermal growth factor-induced survival pathways.

Cellular receptors for the Epidermal Growth Factor are considered important targets for the experimental treatment of human cancer. Monoclonal antibodies as well as small tyrosine kinase inhibitors have been developed and have undergone extensive evaluation in preclinical and clinical studies. Most of these studies have been conceived on the general idea that epidermal growth factor receptor (EGFR) plays a critical role on the growth and survival of human tumors. This assumption has been derived by the successful development of BCR/ABL tyrosine kinase inhibitors in human chronic myeloid leukemia as well as on the activity of antiCD20 monoclonal antibodies in lymphoproliferative disease and of anti HER2 agents in breast tumors overexpressing the targeted antigens. It is now becoming clear that factors regulating sensitivity to kinase inhibitors may differ from monoclonal antibodies and that the molecules targeted by interferring drugs must be prioritaire for growth and survival of those specific tumors in order to achieve valuable results. Recent evidence of major responses to the EGFR inhibitor Gefitinib in tumors harboring activating mutations in the EGFR appears on line with this concept. In this article we will discuss the significance of targeting the EGFR driven survival pathways. Specifically, we will afford the point of EGFR survival signalling prioritization by means of pharmacological treatment. Finally, we will address the role of profiling technologies and of novel computational system biology-based approaches for identification of innovative strategies for effective targeting of EGFR driven survival pathways.

Isoprenylation of intracellular proteins as a new target for the therapy of human neoplasms: preclinical and clinical implications.

Cell proliferation, differentiation, and survival are regulated by a number of extracellular hormones, growth factors, and cytokines in complex organisms. The transduction of the signals by these factors from the outside to the nucleus often requires the presence of small intracellular proteins (i.e. ras and other small G proteins) that are linked to the plasma membrane through a isoprenyl residue that functions as hydrophobic anchor. Isoprenylation is a complex process regulated by different enzymatic steps that could represent potential molecular targets for anti-cancer strategies. In the present paper the different transduction pathways regulated by some isoprenylated proteins such as ras and other small G proteins are described. Moreover, the molecular mechanisms of the isoprenylation process and the mode of action of the different isoprenylation inhibitors are discussed with attention to statins, farnesyltransferase inhibitors (FTI) and aminobisphosphonates. The role of different candidate targets in the determination of anti-tumour effects by FTIs is also described in order to define potential molecular markers predictor of clinical response. On the basis of several preclinical data, new strategies based on multi-step enzyme inhibition or on target prioritization are proposed in order to enhance the anti-tumour activity of agents inhibiting isoprenylation. Finally, a summary of the principal data on clinical trials based on the use of FTIs and statins is given. In conclusion, the inhibition of isoprenylation is an attractive, but still not completely investigated therapeutic alternative that requires optimization for the translation in the current treatment of neoplasms.

Growth inhibition and synergistic induction of apoptosis by zoledronate and dexamethasone in human myeloma cell lines.

Bisphosphonates (BPs) are commonly used in the treatment of myeloma-associated osteolytic lesions. Recent reports have suggested that BPs may also exert direct antitumor effects on myeloma cells. Here, we show that the treatment of myeloma cell lines with the combination of the potent BP zoledronate and dexamethasone inhibits cell growth and synergistically induces apoptotic cell death, providing a rationale for potential applications in vivo.