A framework to rank genomic alterations as targets for cancer precision medicine: the ESMO Scale for Clinical Actionability of molecular Targets (ESCAT)

Background

In order to facilitate implementation of precision medicine in clinical management of cancer, there is a need to harmonise and standardise the reporting and interpretation of clinically relevant genomics data.

Methods

The European Society for Medical Oncology (ESMO) Translational Research and Precision Medicine Working Group (TR and PM WG) launched a collaborative project to propose a classification system for molecular aberrations based on the evidence available supporting their value as clinical targets. A group of experts from several institutions was assembled to review available evidence, reach a consensus on grading criteria and present a classification system. This was then reviewed, amended and finally approved by the ESMO TR and PM WG and the ESMO leadership.

Results

This first version of the ESMO Scale of Clinical Actionability for molecular Targets (ESCAT) defines six levels of clinical evidence for molecular targets according to the implications for patient management: tier I, targets ready for implementation in routine clinical decisions; tier II, investigational targets that likely define a patient population that benefits from a targeted drug but additional data are needed; tier III, clinical benefit previously demonstrated in other tumour types or for similar molecular targets; tier IV, preclinical evidence of actionability; tier V, evidence supporting co-targeting approaches; and tier X, lack of evidence for actionability.

Conclusions

The ESCAT defines clinical evidence-based criteria to prioritise genomic alterations as markers to select patients for targeted therapies. This classification system aims to offer a common language for all the relevant stakeholders in cancer medicine and drug development.

PD-1 blockade therapy in renal cell carcinoma: current studies and future promises

RCC is considered an immunogenic tumor with a prominent dysfunctional immune cell infiltrate, unable to control tumor growth. Evasion of immune surveillance, a process defined immune-editing, leads to malignant progression. The striking improvement of knowledge in immunology has led to the identification of immune checkpoints (such as CTLA-4 and PD-1), whose blockage enhances the antitumor immunity. The interaction between PD-1, an inducible inhibitory receptor expressed on lymphocytes and DCs, and PD-L1 ligand, expressed by tumor cells, results in a down-regulation of the T-cell response. Therefore, the PD-1/PD-L1 axis inhibition by targeted-antibodies, increasing the T-cell proliferation and cytotoxicity, represents a promising mechanism to stimulate the anti-tumor activity of the immune system, improving the outcomes of cancer patients. Several PD-1 and PD-L1 inhibitors have been evaluated in different tumor types, showing promising results. The interesting correlation between lymphocytes PD-1 expression and RCC advanced stage, grade and prognosis, as well as the selective PD-L1 expression by RCC tumor cells and its potential association with worse clinical outcomes, have led to the development of new anti PD-1/PD-L1 agents, alone or in combination with anti-angiogenic drugs or other immunotherapeutic approaches, for the treatment of RCC. In this review we discuss the role of PD-1/PD-L1 in RCC, focusing on the biological rationale, current clinical studies and promising therapeutic perspectives to target the PD-1 pathway.

Antitumor activity of combined blockade of epidermal growth factor receptor and protein kinase A

BACKGROUND

Epidermal growth factor (EGF)-related proteins, such as transforming growth factor-alpha (TGF-alpha), control cancer cell growth through hormonal pathways (i.e., autocrine [hormone acts on cell that produces it] and paracrine [hormone acts on nearby cells] pathways). Overexpression of TGF-alpha and/or its receptor (EGFR) has been detected in human cancers. The blockade of EGFR activation by the use of anti-EGFR monoclonal antibodies (MAbs) has been proposed as a potential anticancer therapy. The type I cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKAI) is generally overexpressed in human cancer cells and is involved in neoplastic transformation. Inhibition of PKAI by selective cAMP analogues, such as 8-chloro-cAMP (8-CI-cAMP), induces growth inhibition in various human cancer cell lines.

PURPOSE

On the basis of our previous observations of a cooperative anti-proliferative effect of anti-EGFR Mab 528 and 8-Cl-cAMP in human cancer cell lines in vitro, we evaluated the anticancer activity in vivo of the combination of an anti-EGFR MAb (MAb C225) and 8-Cl-cAMP.

METHODS

Athymic mice were injected subcutaneously with 10(7) human colon carcinoma GEO cells. After 7 days, when established tumor xenografts of 0.30-0.35 cm3 were detectable, 10-15 mice per group were treated intraperitoneally twice weekly with different doses of 8-Cl-cAMP and/or MAb C225. Cancer cell expression of various growth factors was evaluated by immunohistochemical analysis in tumors obtained from control and treated mice. Data were evaluated for statistical significance using the Student's t test and the Mantel-Cox logrank test. All P values represent two-sided tests of statistical significance.

RESULTS

A 5-week treatment with low doses of 8-Cl-cAMP (0.5 mg/dose) and MAb C225 (0.25 mg/dose) blocked GEO tumor growth (compared with that in control mice; P < .00001) and suppressed cancer cell production of autocrine growth factors, such as TGF-alpha, amphiregulin, and CRIPTO, and of angiogenic (promotes new blood vessel formation) factors, such as vascular endothelial growth factor and basic fibroblast growth factor, with no signs of toxicity. Control and 8-Cl-cAMP (0.5 mg/dose)-treated mice died within 9-10 weeks after tumor cell injection. In MAb C225 (0.25 mg/dose)-treated mice, GEO tumors resumed a growth rate comparable to that in control animals within 3 weeks following the end of treatment and the mice died between 11 and 20 weeks after tumor cell injection. GEO tumor growth was significantly delayed in the MAb C225 plus 8-Cl-cAMP treatment group (P < .00001) and was accompanied by a prolonged survival of mice (P < .00001) as compared with the control group.

CONCLUSIONS

Long-term treatment with a combination of agents that selectively inhibit two intracellular signal-transduction enzymes, such as the PKAI serine-threonine kinase and the EGFR tyrosine kinase, has anticancer activity in vivo, reflected by suppression of tumor proliferation and angiogenesis, with no signs of toxicity.

IMPLICATIONS

Since these inhibitors of intracellular mitogenic (growth-stimulating) signaling have a different mechanism(s) of action and do not antagonize the effects of cytotoxic therapy, a combination of anti-EGFR MAb C225 and 8-Cl-cAMP should be investigated as a nontoxic, long-term treatment for cancer patients following chemotherapy.

Sequence-dependent antiproliferative effects of cytotoxic drugs and epidermal growth factor receptor inhibitors

BACKGROUND

Epidermal growth factor receptor (EGFR) inhibitors are in clinical development in cancer treatment. Preclinical studies have shown potential antitumor efficacy of these agents in combination with chemotherapy or with radiotherapy. However, controversial results have been obtained in different clinical trials.

MATERIALS AND METHODS

The effects on proliferation, cell cycle distribution and induction of apoptosis of three different anti-EGFR agents (gefitinib, ZD6474, cetuximab) were evaluated in different sequences of combination with either a platinum derivative (cisplatin, carboplatin, oxaliplatin) or a taxane (docetaxel, paclitaxel) in KYSE30 cells, a model of a human cancer cell line with a functional EGFR autocrine pathway.

RESULTS

The combination of a cytotoxic drug with an EGFR inhibitor caused different antiproliferative effects on KYSE30 cancer cells depending on the treatment schedule. An antagonistic effect was observed when treatment with each EGFR inhibitor was done before chemotherapy. In contrast, a synergistic antiproliferative activity was obtained when chemotherapy was followed by treatment with EGFR antagonists. This effect was accompanied by potentiation of apoptosis and arrest of the surviving cancer cells in the G(2)/M phases of the cell cycle.

CONCLUSIONS

This study provides a rationale for the evaluation of a potentially synergistic sequence of cytotoxic drugs and EGFR inhibitors in a clinical setting.

Interaction between the epidermal growth factor receptor (EGFR) and the vascular endothelial growth factor (VEGF) pathways: a rational approach for multi-target anticancer therapy

Over the last decade, the concept of targeted biological therapy for the treatment of cancer has emerged. However, a better understanding of these targets and their role in tumor cells and in the surrounding stromal cells is required. Two interesting biological targets are the epidermal growth factor receptor (EGFR) and the vascular endothelia growth factor (VEGF) and its receptors. A number of agents that target these pathways have been described. Many of these are currently in clinical trials and a few have recently been approved by the regulatory authorities in USA and in the European Union. The molecular pathways involved in the proliferation of cancer cells and in tumor-related angiogenesis are very complex and the interference with only a single step of these pathways may often reveal an insufficient therapeutic approach. Moreover, cancer cells have an inherent ability to harness different growth factor signaling pathways for growth advantage and cell survival, a process that may even be facilitated by the use of selective targeted agents. Because of these escape mechanisms, monotherapy with selective targeted agents is unlikely to be a fully effective cancer treatment. For these reasons, targeting different pathways is an attractive and effective therapeutic strategy with a strong rationale for investigating this approach in the clinic. This review focuses on the preclinical rationale of combining targeted agents such as EGFR and VEGF inhibitors in the treatment of cancer and on the clinical trials that have emerged from these studies.

Differential immunohistochemical detection of transforming growth factor alpha, amphiregulin and CRIPTO in human normal and malignant breast tissues

The expression of growth factors, such as transforming growth factor alpha (TGF alpha), amphiregulin (AR) and CRIPTO, a type-1 tyrosine-kinase growth factor receptor (erbB-2), and a tumor-suppressor gene (p53), that have been implicated in the development and/or the progression of breast cancer, was evaluated by immunohistochemistry in 100 human primary infiltrating breast carcinomas (IBC). AR and CRIPTO immunoreactivity was also assessed in 55 human breast ductal carcinomas in situ (DCIS). Within the 100 IBC, 80, 50, 73, 17, and 34 tumors expressed moderate to high levels of TGF alpha, AR, CRIPTO, erbB-2, and p53 respectively. In addition, AR and CRIPTO immunoreactivity were found in 11 and in 26 out of 55 DCIS respectively. In contrast, only 4, 3, and 2 out of 10 normal mammary-gland samples were weakly positive for TGF alpha, AR, and CRIPTO expression, respectively, whereas none was positive for erbB-2 or p53. Within the 100 IBC, expression of erbB-2 significantly correlated with high histologic and nuclear grading, with high growth fraction, and with estrogen-receptor (ER)- and progesterone-receptor (PgR)-negative tumors. A statistically significant correlation was also observed between p53 expression and high histologic grading, high growth fraction, and PgR-negative tumors. In contrast, no significant correlations were found between TGF alpha, AR, and CRIPTO immunoreactivity and various clinicopathological parameters, with the exception of a positive correlation between TGF alpha and ER expression. These data demonstrate that TGF alpha, AR, and CRIPTO expression are significantly increased in malignant mammary epithelium relative to normal epithelium. In particular, the differential expression of CRIPTO may serve as a potential tumor marker for breast carcinogenesis.

Phase II study of gefitinib in combination with docetaxel as first-line therapy in metastatic breast cancer

We have evaluated the activity and safety of gefitinib, a small-molecule epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor, in combination with docetaxel as first-line treatment of women with metastatic breast cancer (MBC). In total, 41 patients with MBC were enrolled in a first-line combination therapy study with oral gefitinib (250 mg day⁻¹) and intravenous docetaxel (75 mg m⁻², the first 14 patients; or 100 mg m⁻², the following 27 patients, on day 1 of a 3-week cycle). Out of 41 patients, 38 received at least one cycle of therapy. There were no differences in activity or tolerability between the two docetaxel doses. G3/4 toxicities were neutropenia (49%), diarrhoea (10%), acne-like rash (5%), and anaemia (2%). Complete plus partial responses (CR+PR) were observed in 22 out of 41 patients with a 54% response rate (95% confidence interval (CI) 45–75%). The 22 patients that achieved a response following six cycles of docetaxel plus gefitinib continued gefitinib monotherapy (median duration, 24 weeks; range, 2–108+ weeks). Two patients with PR following combination therapy achieved a CR during gefitinib monotherapy. Complete plus partial responses correlated with oestrogen receptor (ER) status, since they occurred in 19 out of 27 (70%) patients with ER-positive tumours as compared to three out of 14 (21%) patients with ER-negative tumours (P=0.01).

Site-selective cyclic AMP analogs provide a new approach in the control of cancer cell growth

Site-selective cyclic AMP analogs bind to site 1 or site 2 of the known cAMP-binding sites depending on the position of substituents on the purine ring, either at C-2 and C-8 (site 1) or at C-6 (site 2). The growth inhibitory effect of such site-selective cAMP analogs used in this investigation with 15 human cancer cell lines surpassed that of analogs previously tested. The most potent analogs were 8-chloro, N6-benzyl and N6-phenyl-8-p-chlorophenylthio-cAMP. The combination of a C-8 with an N6 analog had synergistic effects. The 24 site-selective analogs tested produced growth inhibition ranging from 30 to 80% at micromolar concentrations with no sign of toxic effects. Growth inhibition was not due to a block in a specific phase of the cell cycle but paralleled a change in cell morphology, an increase of the RII cAMP receptor protein and a decrease of p21 ras protein. Since the adenosine counterpart of the 8-chloro analog produced G1 synchronization without affecting the RII and p21 ras protein levels, it is unlikely that an adenosine metabolite is involved in the analog effect. Site-selective cAMP analogs thus provide a new biological tool for control of cancer growth.

Antisense oligonucleotides targeting the epidermal growth factor receptor inhibit proliferation, induce apoptosis, and cooperate with cytotoxic drugs in human cancer cell lines

We have constructed a series of 22 phosphorothioate 20-mer antisense oligonucleotides directed against different regions of the human (EGFR) mRNA. Treatment with EGFR antisense oligonucleotides showed a dose-dependent inhibition of human GEO colon cancer cell growth in soft agar. Western blot analysis demonstrated a significant reduction in EGFR expression after treatment with each EGFR antisense oligonucleotide. The ability to inhibit GEO anchorage-independent growth, however, varied among the EGFR antisense sequences with an IC(50) ranging between 0.5 and 3.5 microM. Two of these antisense oligonucleotides targeting the regions between 2457-2476 and 614-4633 bases of the human EGFR mRNA have been modified as hybrid DNA/RNA mixed backbone oligonucleotides (MBO) to examine their anticancer properties in vivo. The 2 EGFR antisense MBOs retained the same biological properties of the fully phosphorothioate EGFR antisense oligonucleotides targeting the same EGFR mRNA sequences, such as blocking EGFR synthesis, inhibiting cell growth and enhancing programmed cell death in human cancer cell lines that express functional EGFRs. Furthermore, a potentiation in the growth inhibitory effect on GEO cancer cells was observed after treatment with these EGFR antisense MBOs in combination with cytotoxic drugs, including cisplatin, doxorubicin, paclitaxel, or topotecan. These results show the antiproliferative activity of specific EGFR antisense oligonucleotides and allow to identify novel EGFR antisense MBOs that deserve further evaluation as potential selective anticancer agents alone or in combination with cytotoxic drugs in human carcinomas that express functional EGFRs.

The RIalpha subunit of protein kinase A (PKA) binds to Grb2 and allows PKA interaction with the activated EGF-receptor

Functional interactions between protein kinase A (PKA) and epidermal growth factor receptor (EGF-R) signalling pathways have been suggested. Unlike the type II isoform of PKA (PKAII), the type I (PKAI) and/or its regulatory subunit RIalpha are generally overexpressed in cancer cells and are induced following transforming growth factor alpha (TGF alpha)/EGF-R-dependent transformation. Downregulation of RIalpha/PKAI inhibits TGF alpha expression and EGF-R-dependent signalling. We have previously shown that addition of EGF to quiescent human normal epithelial MCF-10A cells determines PKAI expression and cell membrane translocation before cells enter S phase, while PKAI inhibition prevents S phase entry. Constitutive overexpression of PKAI confers the ability to grow in serum free medium, bypassing EGF requirement. Here we demonstrate a direct interaction of PKAI, but not of PKAII, with the activated EGF-R, that occurs within 5 min following EGF treatment of MCF-10A cells. Moreover, induction of mitogen-activated protein kinase (MAPK) activity following EGF-R activation is mimicked by PKAI overexpression and inhibited by downregulators of PKAI. Finally, the PKAI-EGF-R association occurs through the binding of RIalpha to the SH3 domain(s) of Grb2 adaptor protein, thus allowing the recruitment of the PKAI holoenzyme to the activated EGF-R. This is the first demonstration of a direct interaction of PKAI with the activated EGF-R macromolecular signalling complex.

Site-selective cyclic AMP analogs as new biological tools in growth control, differentiation, and proto-oncogene regulation

The physiologic role of cyclic adenosine monophosphate (cAMP) in the growth control of a spectrum of human cancer lines, including leukemic lines, and v-rasH oncogene-transformed NIH/3T3 cells is demonstrated by the use of site-selective cAMP analogs. These cAMP analogs, which can select either of the two known cAMP binding sites of the cAMP receptor protein, induce potent growth inhibition, phenotypic change, and differentiation (leukemic cells) of cancer cells at micromolar concentrations with no sign of cytotoxicity. The growth inhibition parallels selective modulation of cAMP-dependent protein kinase isozymes, type I versus type II, and suppression of cellular proto-oncogene expression. Site-selective cAMP analogs thus provide new biological tools for investigating cell proliferation and differentiation and also for the improved management of human cancers.

Selective modulation of protein kinase isozymes by the site-selective analog 8-chloroadenosine 3',5'-cyclic monophosphate provides a biological means for control of human colon cancer cell growth

Differential expression of type I and type II cAMP-dependent protein kinase isozymes has been linked to growth regulation and differentiation. We examined the expression of protein kinase isozymes in the LS 174T human colon cancer cell line during 8-chloroadenosine 3',5'-cyclic monophosphate (8-Cl-cAMP)-induced growth inhibition. Two species of RII (the regulatory subunit of protein kinase type II) with apparent Mr 52,000 (RII52) and Mr 56,000 (RII56) and a single species of RI (the regulatory subunit of protein kinase type I) with Mr 48,000 were identified in the cancer cells. RI and both forms of RII were covalently labeled with 8-azidoadenosine 3',5'-cyclic [32P]monophosphate, and two anti-RII antibodies that exclusively recognize either RII52 or RII56 resolved two forms of the RII receptors. 8-Cl-cAMP treatment induced a decrease of RI and an increase of both RII52 and RII56 in the cytosols of cancer cells and rapid translocation (within 10 min) of RII52 from the cytosol to nucleus. 8-Cl-cAMP caused transcriptional activation of the RII52 receptor gene and inactivation of the RI receptor gene. It also exhibited high-affinity site-1-selective binding to the purified preparations of both RII receptor proteins. Thus, differential regulation of various forms of cAMP receptor proteins is involved in 8-Cl-cAMP-induced regulation of cancer cell growth, and nuclear translocation of RII52 receptor protein appears to be an early event in such differential regulation.

Cooperative inhibition of renal cancer growth by anti-epidermal growth factor receptor antibody and protein kinase A antisense oligonucleotide

BACKGROUND

The expression of epidermal growth factor receptor (EGFR) and type I cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKAI) is associated with neoplastic transformation. By use of human renal cancer cell lines (i.e., 769-P, ACHN, A498, and SW839), we investigated the antiproliferative activity and the antitumor activity of an anti-EGFR humanized chimeric mouse monoclonal antibody, MAb C225, and a novel mixed backbone 18-mer antisense oligonucleotide, HYB 190, that targets expression of the RIalpha regulatory subunit of PKAI.

METHODS

The antiproliferative activity of MAb C225 and oligonucleotide HYB 190, alone or in combination, on different renal cancer cell lines was determined by monitoring cell growth in soft agar. In addition, the induction of apoptosis by treatment with the anti-EGFR antibody and/or antisense PKAI oligonucleotides was evaluated by flow cytometric analysis of fragmented DNA. The antitumor activity of MAb C225 and oligonucleotide HYB 190 was determined in athymic mice bearing established ACHN tumor xenografts. Cell proliferation and tumor growth data were evaluated for statistical significance using Student's t test; reported P values are two-sided.

RESULTS

MAb C225 and oligonucleotide HYB 190 inhibited colony formation in soft agar in a dose-dependent manner for all renal cancer cell lines tested. We observed a potentiation of growth inhibition and induction of apoptosis when 769-P cells and ACHN cells were treated with both agents. Combination treatment with MAb C225 and oligonucleotide HYB 190 caused regression of ACHN tumor xenografts, whereas single-agent treatment only delayed tumor growth.

CONCLUSION

The combination of anti-EGFR MAb C225 and ited cooperative antiproliferative effects and cooperative antitumor effects on EGFR and PKAI-expressing human renal cancer cell lines.

An antisense oligodeoxynucleotide targeted against the type II beta regulatory subunit mRNA of protein kinase inhibits cAMP-induced differentiation in HL-60 leukemia cells without affecting phorbol ester effects

The type II beta regulatory subunit of cAMP-dependent protein kinase (RII beta) has been hypothesized to play an important role in the growth inhibition and differentiation induced by site-selective cAMP analogs in human cancer cells, but direct proof of this function has been lacking. To address this issue, HL-60 human promyelocytic leukemia cells were exposed to RII beta antisense synthetic oligodeoxynucleotide, and the effects on cAMP-induced growth regulation were examined. Exposure of these cells to RII beta antisense oligodeoxynucleotide resulted in a decrease in cAMP analog-induced growth inhibition and differentiation without apparent effect on differentiation induced by phorbol esters. This loss in cAMP growth regulatory function correlated with a decrease in basal and induced levels of RII beta protein. Exposure to RII beta sense, RI alpha and RII alpha antisense, or irrelevant oligodeoxynucleotides had no such effect. These results show that the RII beta regulatory subunit of protein kinase plays a critical role in the cAMP-induced growth regulation of HL-60 leukemia cells.

8-chloro-cAMP inhibits smooth muscle cell proliferation in vitro and neointima formation induced by balloon injury in vivo

OBJECTIVES

The aims of the present study were to assess 1) the effect of 8-C1-cAMP (cyclic-3'-5'-adenosine monophosphate) on vascular smooth muscle cell (VSMC) proliferation in vitro and 2) the efficacy of systemic administration of 8-C1-cAMP on neointimal formation after balloon injury in vivo.

BACKGROUND

Neointimal formation after vascular injury is responsible for restenosis after arterial stenting. Recently, 8-C1-cAMP, a cAMP analogue that induces growth arrest, has been safely administered in phase I studies in humans.

METHODS

The effect of 8-C1-cAMP on cell proliferation was first assessed on SMCs in vitro. To study the effects of cAMP in vivo, balloon injury was performed in 67 rats using a 2F Fogarty balloon catheter.

RESULTS

The 8-C1-cAMP markedly inhibited VSMC proliferation in vitro, reduced protein kinase A (PKA) RIalpha subunit expression, and induced PKA RIIbeta subunit expression. In addition, 8-C1-cAMP reduced, in a dose-dependent manner, neointimal area and neointima/media ratio after balloon injury. The proliferative activity, assessed by proliferating nuclear cell antigen immunostaining, revealed a reduction of proliferative activity of VSMCs in vivo in the 8-C1-cAMP group. Moreover, the systemic administration of 8-C1-cAMP did not affect renal function, blood pressure and heart rate.

CONCLUSIONS

We conclude that 8-C1-cAMP potently inhibits VSMC proliferation in vitro and reduces neointima formation by balloon injury in vivo after systemic administration. These data may have a clinical relevance in designing future strategies to prevent restenosis after arterial stenting and perhaps after percutaneous transluminal coronary angioplasty.

A clinical-biological risk stratification model for resected gastric cancer: prognostic impact of Her2, Fhit, and APC expression status

BACKGROUND

To obtain a prognostic stratification model for resected gastric cancer patients.

PATIENTS AND METHODS

Clinicopathological and molecular data (expression of Cdx2, Apc, β-catenin, E-cadherin, Fhit, p53, and human epidermal growth factor receptor-2 (Her2); HER2 and TOPO2A gene copy number; PIK3CA mutations; microsatellite instability) were correlated to cancer-specific/overall survival (CSS/OS) using a Cox model. Individual patient probability (IPP) was estimated by logistic equation. A continuous score to identify risk-classes was derived according to the model ratios.

RESULTS

Two-hundred eight patients were studied (median follow-up 20 months). At multivariate analysis, sex, stage, margins, location, nodes, Apc, and Fhit were independent predictors for CSS; the same factors (and age and Her2, except Fhit) predicted OS. Multivariate model predicted IPP with high prognostic accuracy (0.90 for CSS; 0.91 for OS). A two-class model significantly separated low- and high-risk patients for CSS (23.4% and 85.6%, P < 0.0001) and OS (21.4% and 82.0%, P < 0.0001). A three-class model differentiated low-, intermediate-, and high-risk patients for CSS (6.3%, 35.3%, and 88.0%, P < 0.0001) and OS (6.1%, 34.6%, and 86.5%, P < 0.0001).

CONCLUSIONS

A risk classification system comprising the immunohistochemical expression of three proteins (Apc, Fhit, and Her2) and five clinicopathological parameters (stage, resected nodes, margins, location, and sex) accurately separates the resected gastric cancer patients into three classes of risk.

Role of site-selective cAMP analogs in the control and reversal of malignancy

Two isoforms of cAMP receptor protein, RI and RII, the regulatory subunits of cAMP-dependent protein kinase, transduce opposite signals, the RI being stimulatory and the RII being inhibitory of cell proliferation. In normal cells RI and RII exist at a specific physiological ratio whereas in cancer cells such physiological balance of these receptor proteins is disrupted. Reversal and suppression of malignancy can be achieved when the physiologic ratio of these intracellular signal transducers of cAMP is restored as shown by the use of site-selective cAMP analogs, antisense oligodeoxynucleotides or gene transfer, suggesting new approaches to cancer control.

Sorafenib in combination with erlotinib or with gemcitabine in elderly patients with advanced non-small-cell lung cancer: a randomized phase II study

BACKGROUND

Sorafenib is a small-molecule multitargeted kinase inhibitor that blocks the activation of C-RAF, B-RAF, c-KIT, FLT-3, RET, vascular endothelial growth factor receptor 2 (VEGFR-2), VEGFR-3 and platelet-derived growth factor receptor β. The aim of this multicenter, randomized phase II study was to evaluate clinical activity and safety of sorafenib in combination with erlotinib or gemcitabine in unselected untreated elderly patients with non-small-cell lung cancer (NSCLC).

METHODS

The trial was designed to select the most promising sorafenib-containing combination in previously untreated elderly (≥70 years) stage IIIB or IV NSCLC patients, with performance status of zero to two. Patients were randomly assigned to one of the following combinations: gemcitabine, 1200 mg/m(2) days 1 and 8, every 21 days, for a maximum of six cycles, plus sorafenib, 800 mg/day, until disease progression or unacceptable toxicity (arm 1); or erlotinib, 150 mg/day, plus sorafenib, 800 mg/day, until disease progression or unacceptable toxicity (arm 2). A selection design was applied with 1-year survival rate as the primary end point of the study, requiring 58 patients.

RESULTS

Sixty patients were randomly allocated to the study (31 patients in arm 1 and 29 patients in arm 2). After a median follow-up of 15 months, 10 patients [32%, 95% confidence interval (CI) 16% to 49%] in arm 1 and 13 patients (45%, 95% CI 27% to 63%) in arm 2 were alive at 1 year. Median overall survival was 6.6 and 12.6 months in arm 1 and arm 2, respectively. Observed toxic effects were consistent with the expected drug profiles.

CONCLUSIONS

The combination of erlotinib and sorafenib was feasible in elderly patients with advanced NSCLC and was associated with a higher 1-year survival rate than the other arm. According to the selection design, this combination warrants further investigation in phase III trials.

New toxicity profile for novel immunotherapy agents: focus on immune-checkpoint inhibitors

INTRODUCTION

Tumor development results from a cancer-induced immunosuppression (immune-editing). Immunotherapy has revolutionized the treatment paradigm for many malignancies, putting clinicians before novel toxicities, of immune-mediated etiology (immune-related adverse events).

AREAS COVERED

Immune-mediated toxicity depends on both innate and adaptive immunity mechanisms. Healthy tissue damage depends on an aspecific T-cell hyperactivation response causing cross-reaction with normal tissues, which leads to an overproduction of CD4 T-helper cell cytokines and an abnormal migration of cytolytic CD8 T-cells. By stimulating a diffuse T-cell repertoire expansion, immune-checkpoint inhibitors counteract tumor growth but reduce the self-tolerance, damaging healthy organs. In this review, we summarize the toxicity profile of the novel immune-checkpoint inhibitors and their clinical implications, we are convinced that a deep understanding and a prompt resolution of the paradigmatic toxicities of these drugs will result in clinical benefits to patients and an enhanced antitumor effect.

EXPERT OPINION

A focus on immunotoxicity is important in the education of clinicians and will improve patient safety. There is a willingness to tailor specific immune-therapies to each cancer patient, and to stimulate researchers through understanding of the physiopathogenesis, using the hypothesis that immune-mediated toxicities can be used as predictors of response or a prognostic sign of survival, thereby guiding therapeutic decisions.

Wireless powering for a self-propelled and steerable endoscopic capsule for stomach inspection

This paper describes the integration of an active locomotion module in a wirelessly powered endoscopic capsule. The device is a submersible capsule optimized to operate in a fluid environment in a liquid-distended stomach. A 3D inductive link is used to supply up to 400mW to the embedded electronics and a set of 4 radio-controlled motor propellers. The design takes advantage of a ferrite-core in the receiving coil-set. This approach significantly improves the coupling with the external field source with respect to earlier work by the group. It doubles the power that can be received with a coreless coil-set under identical external conditions. The upper limit of the received power was achieved complying with the strict regulations for safe exposure of biological tissue to variable magnetic fields. The wireless transferred power was proven to be sufficient to achieve the speed of 7cm/s in any directions. An optimized locomotion strategy was defined which limits the power consumption by running only 2 motors at a time. A user interface and a joystick controller allow to fully drive the capsule in an intuitive manner. The device functionalities were successfully tested in a dry and a wet environment in a laboratory set-up.

A novel MDM2 anti-sense oligonucleotide has anti-tumor activity and potentiates cytotoxic drugs acting by different mechanisms in human colon cancer

MDM2 is over-expressed in several human tumors. Its product is a negative-feedback regulator of p53, which interferes with the control of cell proliferation and apoptosis, interacting not only with p53 but also with retinoblastoma (Rb) and E2F. Moreover, mutations in the ARF-Ink4a locus may also allow MDM2 to override p53 functions. In this study, we have used a novel oligonucleotide anti-sense MDM2, with mixed-backbone structure and demonstrate that it causes inhibition of MDM2 expression, induction of both p53 and p21/WAF1 expression and a dose-dependent, growth-inhibitory effect in human GEO colon-cancer cells. We also show that anti-sense MDM2 has a co-operative growth-inhibitory effect with different classes of cytotoxic drugs acting by different mechanisms. Moreover, anti-sense MDM2 induces apoptosis and markedly enhances the apoptotic activity of different cytotoxic drugs. Finally, we show that anti-sense MDM2 has anti-tumor activity in vivo in nude mice bearing GEO xenografts and potentiates the anti-tumor effect of cytotoxic drugs. Indeed, despite the short treatment period, the combination of anti-sense MDM2 and cytotoxic drugs causes a marked delay in tumor growth and prolongation of mice survival, lasting several months after treatment cessation. The anti-tumor effect is associated with inhibition of MDM2 expression in tumor specimens of animals treated with anti-sense MDM2, alone or in combination with a cytotoxic drug. Our results provide the rationale for development of a novel mixed-backbone anti-sense MDM2 into a clinical setting in therapeutic combination strategies with conventional cytotoxic drugs.

Effect of sod (superoxide dismutase) protein supplementation in semen extenders on motility, viability, acrosome status and ERK (extracellular signal-regulated kinase) protein phosphorylation of chilled stallion spermatozoa

New studies are underway to find new methods for supporting longer storage of cooled stallion semen. It is known that high concentrations of reactive oxygen species (ROS) cause sperm pathology. The metalloprotein superoxide dismutase (SOD) is responsible for H(2)O(2) and O(2) production, by dismutation of superoxide radicals. The aim of this study is to assess the quality of chilled stallion semen processed with extenders containing SOD at different concentrations as antioxidant additives. A total of 80 ejaculates collected from 5 standardbred stallions was divided into 5 aliquots treated as: native semen (control 1); native semen diluted 1:3 with Kenney semen extender (control 2); spermatozoa diluted after centrifugation in extender without (control 3) or with SOD at 25 IU/ml (experimental 1) or 50 IU/ml (experimental 2). Each sample was analyzed for motility, viability and acrosome status, immediately after semen preparation and again after storage at 5 °C for 24 h, 48 h and 7 2h. Acrosome integrity was evaluated by Chlortetracycline (CTC) and Fluorescent-labeled peanut lectin agglutinin (PNA-FITC conjugated staining). A proteomic approach of quantifying extracellular signal regulated kinase (ERK) was also evaluated as an indirect indicator of oxidative stress. In all samples sperm progressive motility and sperm acrosomal integrity showed a significant reduction between fresh and cooled spermatozoa at 24 h, 48 h and 72 h. Quality parameters of sperm were significantly higher (Progressive Motility P < 0.01; Viability P < 0.001) in aliquots supplemented with SOD. ERK phosphorylation was statistically higher (P < 0.01) in aliquots without SOD. The Authors concluded that addition of SOD to semen extenders improves the quality of chilled equine semen and reduces ERK activation.

Induction of megakaryocytic differentiation and modulation of protein kinase gene expression by site-selective cAMP analogs in K-562 human leukemic cells

Two classes (site 1- and site 2-selective) of cAMP analogs, which either alone or in combination demonstrate a preference for binding to type II rather than type I cAMP-dependent protein kinase isozyme, potently inhibit growth in a spectrum of human cancer cell lines in culture. Treatment of K-562 human leukemic cells for 3 days with 30 and 10 microM 8-chloroadenosine 3',5'-cyclic monophosphate (8-Cl-cAMP) (site 1-selective) resulted in 60% and 20% growth inhibition, respectively (with over 90% viability). N6-Benzyl-cAMP (site 2-selective) (30 microM) treatment resulted in 20% growth inhibition by day 3. When 8-Cl-cAMP (10 microM) and N6-benzyl-cAMP (30 microM) were both added, growth was almost completely arrested. The growth inhibition was accompanied by megakaryocytic differentiation in K-562 cells. The untreated control cells expressed little or no detectable levels of glycoprotein IIb-IIIa surface antigen complex. 8-Cl-cAMP (30 microM) treatment for 3 days substantially increased the antigen expression, while N6-benzyl-cAMP caused little or no change in the antigen expression. When cells were treated with 8-Cl-cAMP in combination with N6-benzyl-cAMP, antigen expression was synergistically enhanced, and cells demonstrated megakaryocyte morphology. By Northern blotting, we examined the mRNA levels of the type I and type II protein kinase regulatory subunits (RI alpha and RII beta), the catalytic subunit, and c-myc during 8-Cl-cAMP treatment. The steady-state level of RII beta cAMP receptor mRNA sharply increased within 1 hr of treatment and remained elevated for 3 days, while that of the RI alpha receptor markedly decreased to below control level within 6 hr and remained low during treatment. However, 8-Cl-cAMP did not affect the mRNA level of the catalytic subunit. 8-Cl-cAMP treatment also brought about a rapid decrease in c-myc mRNA. Thus, differential regulation of cAMP receptor genes is an early event in cAMP-induced differentiation and growth control of K-562 leukemia cells.

Site-selective 8-chloroadenosine 3',5'-cyclic monophosphate inhibits transformation and transforming growth factor alpha production in Ki-ras-transformed rat fibroblasts

A site-selective cAMP analog, 8-chloroadenosine 3',5'-cyclic monophosphate (8-Cl-cAMP), was demonstrated to be a potent inhibitor of both the monolayer and soft agar growth of normal rat kidney (NRK) fibroblasts that had been transformed with the v-Ki-ras oncogene or treated with transforming growth factor alpha (TGF alpha). The growth inhibition was dose dependent and reversible and was accompanied by reversion of the transformed phenotype, suppression of TGF alpha production, and a decrease in p21 ras protein levels. These effects of 8-Cl-cAMP were linked to the cAMP analog's selective modulation of the type I and type II cAMP-dependent protein kinase regulatory subunits, RI and RII, present in Ki-ras-transformed and TGF alpha-treated NRK cells.

Synergistic inhibition of human cancer cell growth by cytotoxic drugs and mixed backbone antisense oligonucleotide targeting protein kinase A

Protein kinase A type I plays a key role in neoplastic transformation, conveying mitogenic signals of different growth factors and oncogenes. Inhibition of protein kinase A type I by antisense oligonucleotides targeting its RIalpha regulatory subunit results in cancer cell growth inhibition in vitro and in vivo. A novel mixed backbone oligonucleotide HYB 190 and its mismatched control HYB 239 were tested on soft agar growth of several human cancer cell types. HYB 190 demonstrated a dose-dependent inhibition of colony formation in all cell lines whereas the HYB 239 at the same doses caused a modest or no growth inhibition. A noninhibitory dose of each mixed backbone oligonucleotide was used in OVCAR-3 ovarian and GEO colon cancer cells to study whether any cooperative effect may occur between the antisense and a series of cytotoxic drugs acting by different mechanisms. Treatment with HYB 190 resulted in an additive growth inhibitory effect with several cytotoxic drugs when measured by soft agar colony formation. A synergistic growth inhibition, which correlated with increased apoptosis, was observed when HYB 190 was added to cancer cells treated with taxanes, platinum-based compounds, and topoisomerase II selective drugs. This synergistic effect was also observed in breast cancer cells and was obtained with other related drugs such as docetaxel and carboplatin. Combination of HYB 190 and paclitaxel resulted in an accumulation of cells in late S-G2 phases of cell cycle and marked induction of apoptosis. A cooperative effect of HYB 190 and paclitaxel was also obtained in vivo in nude mice bearing human GEO colon cancer xenografts. These results are the first report of a cooperative growth inhibitory effect obtained in a variety of human cancer cell lines by antisense mixed backbone oligonucleotide targeting protein kinase A type I-mediated mitogenic signals and specific cytotoxic drugs.