Personalized therapeutic strategies in HER2-driven gastric cancer.

BACKGROUND: Trastuzumab is the only approved targeted therapy in patients with HER2-amplified metastatic gastric cancer (GC). Regrettably, in clinical practice, only a fraction of them achieves long-term benefit from trastuzumab-based upfront strategy. To advance precision oncology, we investigated the therapeutic efficacy of different HER2-targeted strategies, in HER2 "hyper"-amplified (≥ 8 copies) tumors. METHODS: We undertook a prospective evaluation of HER2 targeting with monoclonal antibodies, tyrosine kinase inhibitors and antibody-drug conjugates, in a selected subgroup of HER2 "hyper"-amplified gastric patient-derived xenografts (PDXs), through the design of ad hoc preclinical trials. RESULTS: Despite the high level of HER2 amplification, trastuzumab elicited a partial response only in 2 out of 8 PDX models. The dual-HER2 blockade with trastuzumab plus either pertuzumab or lapatinib led to complete and durable responses in 5 (62.5%) out of 8 models, including one tumor bearing a concomitant HER2 mutation. In a resistant PDX harboring KRAS amplification, the novel antibody-drug conjugate trastuzumab deruxtecan (but not trastuzumab emtansine) overcame KRAS-mediated resistance. We also identified a HGF-mediated non-cell-autonomous mechanism of secondary resistance to anti-HER2 drugs, responsive to MET co-targeting. CONCLUSION: These preclinical randomized trials clearly indicate that in HER2-driven gastric tumors, a boosted HER2 therapeutic blockade is required for optimal efficacy, leading to complete and durable responses in most of the cases. Our results suggest that a selected subpopulation of HER2-"hyper"-amplified GC patients could strongly benefit from this strategy. Despite the negative results of clinical trials, the dual blockade should be reconsidered for patients with clearly HER2-addicted cancers.

Healthy lifestyle promotion in primary schools through the board game Kaledo: a pilot cluster randomized trial.

The board game Kaledo was proven to be effective in improving nutrition knowledge and in modifying dietary behavior in students attending middle and high school. The present pilot study aims to reproduce these results in younger students (7-11 years old) attending primary school. A total of 1313 children from ten schools were recruited to participate in the present study. Participants were randomized into two groups: (1) the treatment group which consisted of playing Kaledo over 20 sessions and (2) the no intervention group. Anthropometric measures were carried out for both groups at baseline (prior to any treatment) and at two follow-up post-assessments (8 and 18 months). All the participants completed a questionnaire concerning physical activity and a 1-week food diary at each assessment. The primary outcomes were (i) BMI z-score, (ii) scores on physical activity, and (iii) scores on a dietary questionnaire. BMI z-score was significantly lower in the treated group compared to the control group at 8 months. Frequency and duration of self-reported physical activity were also significantly augmented in the treated group compared to the control group at both post-assessments. Moreover, a significant increase in the consumption of healthy food and a significant decrease in junk food intake were observed in the treated group. CONCLUSION: The present results confirm the efficacy of Kaledo in younger students in primary schools, and it can be used as a useful nutritional tool for obesity prevention programs in children. What is Known: • Kaledo is a new educational board game to improve nutrition knowledge and to promote a healthy lifestyle. • In two cluster randomized trials conducted in Campania region (Italy), we showed that Kaledo could improve nutrition knowledge and dietary behavior and have a positive effect on the BMI z-score in children with age ranging from 9 to 14 years old attending school. • Kaledo may be used as an effective tool for obesity prevention programs in middle and high school students. What is New: • Investigating the effects of Kaledo on younger primary school children (7-11 year olds), Kaledo could be an effective tool in obesity prevention programs for children as young as 7 years old.

Optimized EGFR Blockade Strategies in EGFR Addicted Gastroesophageal Adenocarcinomas.

PURPOSE: Gastric and gastroesophageal adenocarcinomas represent the third leading cause of cancer mortality worldwide. Despite significant therapeutic improvement, the outcome of patients with advanced gastroesophageal adenocarcinoma is poor. Randomized clinical trials failed to show a significant survival benefit in molecularly unselected patients with advanced gastroesophageal adenocarcinoma treated with anti-EGFR agents. EXPERIMENTAL DESIGN: We performed analyses on four cohorts: IRCC (570 patients), Foundation Medicine, Inc. (9,397 patients), COG (214 patients), and the Fondazione IRCCS Istituto Nazionale dei Tumori (206 patients). Preclinical trials were conducted in patient-derived xenografts (PDX). RESULTS: The analysis of different gastroesophageal adenocarcinoma patient cohorts suggests that EGFR amplification drives aggressive behavior and poor prognosis. We also observed that EGFR inhibitors are active in patients with EGFR copy-number gain and that coamplification of other receptor tyrosine kinases or KRAS is associated with worse response. Preclinical trials performed on EGFR-amplified gastroesophageal adenocarcinoma PDX models revealed that the combination of an EGFR mAb and an EGFR tyrosine kinase inhibitor (TKI) was more effective than each monotherapy and resulted in a deeper and durable response. In a highly EGFR-amplified nonresponding PDX, where resistance to EGFR drugs was due to inactivation of the TSC2 tumor suppressor, cotreatment with the mTOR inhibitor everolimus restored sensitivity to EGFR inhibition. CONCLUSIONS: This study underscores EGFR as a potential therapeutic target in gastric cancer and identifies the combination of an EGFR TKI and a mAb as an effective therapeutic approach. Finally, it recognizes mTOR pathway activation as a novel mechanism of primary resistance that can be overcome by the combination of EGFR and mTOR inhibitors.See related commentary by Openshaw et al., p. 2964.

Pro-metastatic splicing of Ron proto-oncogene mRNA can be reversed: therapeutic potential of bifunctional oligonucleotides and indole derivatives.

Alternative splicing is a key molecular mechanism for increasing the complexity of the human transcriptome. Nearly all human genes are regulated by alternative splicing and the deregulation of this process has a causative role in various human diseases, including cancer. The discovery that alternatively spliced isoforms of several genes are expressed selectively in tumor cells opened the exciting possibility that pharmacological treatment of aberrant splicing could lead to new anti-cancer therapeutic approaches. An alternatively spliced isoform of a scatter factor receptor and proto-oncogene, Ron, accumulates during tumor progression of epithelial tissues and is able to confer an invasive phenotype to the expressing cells. This isoform, called ΔRon, originates from skipping of exon 11, and this specific splicing event is controlled by the expression level of the splicing factor and proto-oncogene SF2/ASF. Over-expression of SF2/ASF, which occurs frequently in various human tumors, induces the production of ΔRon and activates the epithelial to mesenchymal transition (EMT), leading to increased cell motility. In this paper, we have used targeted oligonucleotide enhancers of splicing (TOES) to recruit positive splicing factors to Ron exon 11 and thereby stimulate its inclusion. As an alternative approach, we have used selected indole derivatives that target ASF/SF2 splicing activity. Both treatments correct aberrant ΔRon splicing, restoring the incorporation of Ron exon 11. Notably, indole derivatives are also able to affect the invasive phenotype of the cells. Thus, these treatments may have therapeutic applications for anti-cancer purposes.

Modality-specific naming impairment after traumatic brain injury (TBI).

OBJECTIVE: To investigate neurocognitive and language functions in a single case presenting with modality-specific naming difficulties secondary to traumatic brain injury (TBI). DESIGN: A comprehensive neuropsychological testing and specific assessment of naming and recognition functions were administered. Follow-up testing was administered 2 years post-injury to evaluate syndrome evolution. Rehabilitative intervention is described. RESULTS: Ability to name visually presented objects was greatly impaired. The patient can describe or demonstrate the use of objects she cannot name and to sort them into their appropriate categories, indicating adequate non-verbal recognition. The impairment is specific to visual naming, as recognition through modalities different from vision is adequate (e.g. by touching the object, hearing its sound or being provided with verbal definition of it). This study and follow-up testing illustrated the evolution of the deficit, from a visual agnosic impairment to the co-occurrence of partial deficit of visual naming of objects and letters (optic aphasia and alexia). CONCLUSION: The patient presents with mild pre-semantic deficit (in mapping visual information with semantics) as well as post-semantic impairments (in the association between semantics and lexical label). Such performance can be accommodated within Farah's formulation which implies superadditive mild damage at several stages of object recognition naming model.

A Comprehensive PDX Gastric Cancer Collection Captures Cancer Cell-Intrinsic Transcriptional MSI Traits.

Gastric cancer is the world's third leading cause of cancer mortality. In spite of significant therapeutic improvements, the clinical outcome for patients with advanced gastric cancer is poor; thus, the identification and validation of novel targets is extremely important from a clinical point of view. We generated a wide, multilevel platform of gastric cancer models, comprising 100 patient-derived xenografts (PDX), primary cell lines, and organoids. Samples were classified according to their histology, microsatellite stability, Epstein-Barr virus status, and molecular profile. This PDX platform is the widest in an academic institution, and it includes all the gastric cancer histologic and molecular types identified by The Cancer Genome Atlas. PDX histopathologic features were consistent with those of patients' primary tumors and were maintained throughout passages in mice. Factors modulating grafting rate were histology, TNM stage, copy number gain of tyrosine kinases/KRAS genes, and microsatellite stability status. PDX and PDX-derived cells/organoids demonstrated potential usefulness to study targeted therapy response. Finally, PDX transcriptomic analysis identified a cancer cell-intrinsic microsatellite instability (MSI) signature, which was efficiently exported to gastric cancer, allowing the identification, among microsatellite stable (MSS) patients, of a subset of MSI-like tumors with common molecular aspects and significant better prognosis. In conclusion, we generated a wide gastric cancer PDX platform, whose exploitation will help identify and validate novel "druggable" targets and optimize therapeutic strategies. Moreover, transcriptomic analysis of gastric cancer PDXs allowed the identification of a cancer cell-intrinsic MSI signature, recognizing a subset of MSS patients with MSI transcriptional traits, endowed with better prognosis. SIGNIFICANCE: This study reports a multilevel platform of gastric cancer PDXs and identifies a MSI gastric signature that could contribute to the advancement of precision medicine in gastric cancer.

Downregulating Neuropilin-2 Triggers a Novel Mechanism Enabling EGFR-Dependent Resistance to Oncogene-Targeted Therapies.

Neuropilins are a class of cell surface proteins implicated in cell migration and angiogenesis, with aberrant expression in human tumors. Here, we show that the expression of Neuropilin-2 (NRP2) controls EGFR protein levels, thereby impinging on intracellular signaling, viability, and response to targeted therapies of oncogene-addicted cells. Notably, increased NRP2 expression in EGFR-addicted tumor cells led to downregulation of EGFR protein and tumor cell growth inhibition. NRP2 also blunted upregulation of an EGFR "rescue" pathway induced by targeted therapy in Met-addicted carcinoma cells. Cancer cells acquiring resistance to MET oncogene-targeted drugs invariably underwent NRP2 loss, a step required for EGFR upregulation. Mechanistic investigations revealed that NRP2 loss activated NFkB and upregulated the EGFR-associated protein KIAA1199/CEMIP, which is known to oppose the degradation of activated EGFR kinase. Notably, KIAA1199 silencing in oncogene-addicted tumor cells improved therapeutic responses and counteracted acquired drug resistance. Our findings define NRP2 as the pivotal switch of a novel broad-acting and actionable pathway controlling EGFR signaling, and driving resistance to therapies targeting oncogene-addiction.Significance: These important findings identify the cell surface molecule Nrp2 as the pivotal switch of a novel, actionable pathway driving EGFR upregulation and resistance to oncogene- targeted therapies. Cancer Res; 78(4); 1058-68. ©2017 AACR.

miR-205 mediates adaptive resistance to MET inhibition via ERRFI1 targeting and raised EGFR signaling.

The onset of secondary resistance represents a major limitation to long-term efficacy of target therapies in cancer patients. Thus, the identification of mechanisms mediating secondary resistance is the key to the rational design of therapeutic strategies for resistant patients. MiRNA profiling combined with RNA-Seq in MET-addicted cancer cell lines led us to identify the miR-205/ERRFI1 (ERBB receptor feedback inhibitor-1) axis as a novel mediator of resistance to MET tyrosine kinase inhibitors (TKIs). In cells resistant to MET-TKIs, epigenetically induced miR-205 expression determined the downregulation of ERRFI1 which, in turn, caused EGFR activation, sustaining resistance to MET-TKIs. Anti-miR-205 transduction reverted crizotinib resistance in vivo, while miR-205 over-expression rendered wt cells refractory to TKI treatment. Importantly, in the absence of EGFR genetic alterations, miR-205/ERRFI1-driven EGFR activation rendered MET-TKI-resistant cells sensitive to combined MET/EGFR inhibition. As a proof of concept of the clinical relevance of this new mechanism of adaptive resistance, we report that a patient with a MET-amplified lung adenocarcinoma displayed deregulation of the miR-205/ERRFI1 axis in concomitance with onset of clinical resistance to anti-MET therapy.

Increased Lactate Secretion by Cancer Cells Sustains Non-cell-autonomous Adaptive Resistance to MET and EGFR Targeted Therapies.

The microenvironment influences cancer drug response and sustains resistance to therapies targeting receptor-tyrosine kinases. However, if and how the tumor microenvironment can be altered during treatment, contributing to resistance onset, is not known. We show that, under prolonged treatment with tyrosine kinase inhibitors (TKIs), EGFR- or MET-addicted cancer cells displayed a metabolic shift toward increased glycolysis and lactate production. We identified secreted lactate as the key molecule instructing cancer-associated fibroblasts to produce hepatocyte growth factor (HGF) in a nuclear factor κB-dependent manner. Increased HGF, activating MET-dependent signaling in cancer cells, sustained resistance to TKIs. Functional or pharmacological targeting of molecules involved in the lactate axis abrogated in vivo resistance, demonstrating the crucial role of this metabolite in the adaptive process. This adaptive resistance mechanism was observed in lung cancer patients progressed on EGFR TKIs, demonstrating the clinical relevance of our findings and opening novel scenarios in the challenge to drug resistance.

Rituximab Treatment Prevents Lymphoma Onset in Gastric Cancer Patient-Derived Xenografts.

Patient-Derived Xenografts (PDXs), entailing implantation of cancer specimens in immunocompromised mice, are emerging as a valuable translational model that could help validate biologically relevant targets and assist the clinical development of novel therapeutic strategies for gastric cancer. More than 30% of PDXs generated from gastric carcinoma samples developed human B-cell lymphomas instead of gastric cancer. These lymphomas were monoclonal, Epstein Barr Virus (EBV) positive, originated tumorigenic cell cultures and displayed a mutational burden and an expression profile distinct from gastric adenocarcinomas. The ability of grafted samples to develop lymphomas did not correlate with patient outcome, nor with the histotype, the lymphocyte infiltration level, or the EBV status of the original gastric tumor, impeding from foreseeing lymphoma onset. Interestingly, lymphoma development was significantly more frequent when primary rather than metastatic samples were grafted. Notably, the development of such lympho-proliferative disease could be prevented by a short rituximab treatment upon mice implant, without negatively affecting gastric carcinoma engraftment. Due to the high frequency of human lymphoma onset, our data show that a careful histologic analysis is mandatory when generating gastric cancer PDXs. Such care would avoid misleading results that could occur if testing of putative gastric cancer therapies is performed in lymphoma PDXs. We propose rituximab treatment of mice to prevent lymphoma development in PDX models, averting the loss of human-derived samples.

Targeted therapies for gastric cancer: failures and hopes from clinical trials.

Gastric cancer is the third leading cause of cancer mortality worldwide. As surgery is the only curative treatment strategy and conventional chemotherapy has shown limited efficacy -with a median overall survival of 10 months- new treatments are urgently needed. Trastuzumab and Ramucirumab (targeting HER2 and VEGFR2, respectively) are the only targeted therapies approved so far. Indeed, most Phase III clinical trials evaluating molecular drugs in gastric cancer failed. This review will retrace the relevant clinical trials with molecular therapies performed in gastric cancer patients, discussing the possible reasons for their failure and indicating new perspective for a real improvement of the treatment of this disease.

Amplification of the MET receptor drives resistance to anti-EGFR therapies in colorectal cancer.

EGF receptor (EGFR)-targeted monoclonal antibodies are effective in a subset of metastatic colorectal cancers. Inevitably, all patients develop resistance, which occurs through emergence of KRAS mutations in approximately 50% of the cases. We show that amplification of the MET proto-oncogene is associated with acquired resistance in tumors that do not develop KRAS mutations during anti-EGFR therapy. Amplification of the MET locus was present in circulating tumor DNA before relapse was clinically evident. Functional studies show that MET activation confers resistance to anti-EGFR therapy both in vitro and in vivo. Notably, in patient-derived colorectal cancer xenografts, MET amplification correlated with resistance to EGFR blockade, which could be overcome by MET kinase inhibitors. These results highlight the role of MET in mediating primary and secondary resistance to anti-EGFR therapies in colorectal cancer and encourage the use of MET inhibitors in patients displaying resistance as a result of MET amplification.