Role of mTOR signaling in tumor microenvironment. An overview

The mammalian target of rapamycin (mTOR) pathway regulates major processes by integrating a variety of exogenous cues, including diverse environmental inputs in the tumor microenvironment (TME). In recent years, it has been well recognized that cancer cells co-exist and co-evolve with their TME, which is often involved in drug resistance. The mTOR pathway modulates the interactions between the stroma and the tumor, thereby affecting both the tumor immunity and angiogenesis. The activation of mTOR signaling is associated with these pro-oncogenic cellular processes, making mTOR a promising target for new combination therapies. This review highlights the role of mTOR signaling in the characterization and the activity of the TME’s elements and their implications in cancer immunotherapy

Defective FoxP3+ Treg cell differentiation in the gut of Type 1 Diabetic patients

Environmental factors that act at the intestinal level such as diet, drugs, and microflora have a high impact on the pathogenesis of autoimmune Type 1 Diabetes (T1D), but it is still unclear how the gut milieu affects autoimmunity outside the intestine. Here we show that peripheral FoxP3+ Treg cell differentiation, a mechanism that takes place in the gut and is crucial to maintain systemic immune tolerance, is impaired in T1D patients. These results provide the first evidence that gut mucosa alteration could predispose to autoimmune T1D by affecting systemic immune regulation

414. CAR Spacers Including NGFR Domains Allow Efficient T-Cell Tracking and Mediate Superior Antitumor Effects

In conclusion, we demonstrated that the incorporation of the LNGFR marker gene directly in the CAR sequence allows for a single molecule to work as a therapeutic and as a selection/tracking gene and shows an increased efficacy/safety profile compared to the IgG1-CH2CH3 spacer

Association between proton-pump inhibitors (PPI) and metronomic capecitabine (MCAP) as salvage treatment for patients with advanced gastro-intestinal tumoursa. A randomized phase II study

Background: Several researches have shown that acidification of tumor microenvironment is the basis for tumor invasiveness, ability to metastasize S382 Abstracts and cytotoxic agents resistance; therefore proton pump inhibitors (PPI) could significantly increase the chemosensitivity. In our retrospective work we have investigated the role of capecitabine (mCAP) at metronomic dosage of 1500 mg/die as salvage chemotherapy in patients with metastatic colorectal cancer, showing a moderately activity and well tolerability. In this prospective study we evaluated safety and activity of mCAP in the advanced gastro-intestinal patients and the putative chemosensitizing activity of a specific PPI (Rabeprazole) in association to this therap

512 the cytokine release syndrome crucially contributes to the anti leukemic effects of cd44v6 car t cells

Background: Despite the remarkable clinical results of CD19 CAR-T cells in B-cell leukemias, their long-term efficacy is limited by the emergence of CD19-loss escape variants. Moreover, whether the cytokine release syndrome (CRS) is necessary for durable remissions is a matter of debate. Currently available xenograft models in NSG mice are not suited for studying the antitumor effects of CAR-T cells beyond 3-4 weeks, because of xenograft-versus-host disease (X-GVHD). Moreover, since NSG mice lack functional myeloid cells, the CRS does not develop. Aim: To verify whether the CRS contributes to the antileukemic effects of CAR in an innovative xenotolerant mouse model.Results: NSG mice triple transgenic for human IL-3, GM-CSF and SCF (NSG-3GS) were sub-lethally irradiated and injected intra-liver with human HSCs soon after birth, enabling an accelerated and better balanced lympho-hematopoietic reconstitution compared with NSG mice. Reconstituting human T cells were single CD4+/CD8+ T cells, representing all memory sub-populations. After ex vivo isolation and activation with CD3/CD28-beads and IL-7/IL-15, NSG-3GS T cells were transduced with a CD44v6 CAR, retaining an early-differentiated (stem-cell/central-memory) phenotype and full antitumor functionality against acute myeloid leukemia (AML). NSG-3GS-derived CD44v6 CAR T cells were subsequently infused in tumor-bearing secondary recipients previously humanized with autologous HSCs. CAR-T cells persisted in vivo for at least 6 months and mediated durable leukemia remissions (P<0.001 vs controls) in the absence of X-GVHD. Tumor clearance associated with an acute malaise syndrome, characterized by high fevers and a surge in human IL-6 levels, which was lethal in 30% of the mice. Differently from CD19 CAR-T cells, the CRS by CD44v6 CAR-T cells was significantly anticipated (3 vs 8 days), coinciding with human CD44v6+ monocyte depletion. In humanized mice, previous myeloid-cell depletion by clodronate administration completely prevented this syndrome, but associated with late leukemia relapses. Conversely, mice developing the CRS entered a state of durable and profound remission, as demonstrated by prolonged observation times and secondary transplantation. Conclusions: By using an innovative xenotolerant mouse model, we have demonstrated that the CRS is needed for sustained antileukemic effects by CD44v6 CAR-T cells

Acute Tolerability of Methylphenidate in Treatment-Naïve Children with ADHD: An Analysis of Naturalistically Collected Data from Clinical Practice

OBJECTIVES: The acute tolerability of methylphenidate (MPH) in children with attention-deficit/hyperactivity disorder (ADHD) has been studied mainly in research samples. Taking advantage of the mandatory test-dose procedure required for starting MPH in Italy, this study aimed to assess the incidence of intolerable adverse events after initial exposure to MPH in routine clinical practice. METHODS: The medical records of 480 consecutively treated, previously drug-naïve children and adolescents with ADHD (90% male, mean age 10.6 ± 3.0 years) were retrospectively analyzed. All children received an initial single dose of MPH immediate release (5 or 10 mg) followed by a 4-hour direct medical observation. Heart rate and blood pressure were measured at dosing and 1, 2, and 3 hours afterwards. If the first dose was well tolerated, the child continued treatment with MPH 5–20 mg daily, and was reassessed a week later. RESULTS: Eleven patients (2.3%, 95% CI 1.1–4.1) interrupted treatment within a week of initiation because of the following adverse events: irritability (n = 3), tics worsening (n = 3), reduced appetite (n = 1), enuresis (n = 1), hallucinations (n = 1), hyperfocus (n = 1), and ‘rebound’ behavioral worsening (n = 1). The most common adverse events were reduced appetite (20%), irritability (14.2%), headache (10.6%), sleep problems (9.4%), stomachache (9.4%), and tics (5%). Intellectual disability increased the risk of any adverse event in general and of irritability in particular. No cardiovascular symptom was clinically reported. However, routine assessments of vital signs during the first 3 hours after the first dose of MPH showed that 9% of the children had a 20% increase in heart rate, 8.8% had a 20% increase in diastolic blood pressure and 4.5% had a 20% increase in systolic blood pressure. Of these, 25.2% still had an elevated heart rate 1 week later. CONCLUSIONS: Among stimulant-naïve children in clinical practice, the incidence of acute MPH intolerance can be estimated to be between 1.2 and 4.1%. An asymptomatic elevation in cardiovascular parameters can be observed in about 1 out of 10 children and warrants monitoring during ongoing treatment

Early changes in plasma DNA levels of mutant KRAS as a sensitive marker of response to chemotherapy in pancreatic cancer

Pancreatic cancer (PDAC) is still lacking of reliable markers to monitor tumor response. CA 19-9 is the only biomarker approved, despite it has several limitations in sensitivity and specificity. Since mutations of KRAS occur in more than 90% of tumors, its detection in circulating free tumor DNA (cftDNA) could represent a biomarker to monitor chemotherapy response. Twenty-seven advanced PDAC patients given first-line 5-fluorouracil, irinotecan and oxaliplatin or gemcitabine and nab-paclitaxel were enrolled. Three ml of plasma were collected: 1) before starting chemotherapy (baseline); 2) at day 15 of treatment; and 3) at each clinical follow-up. cftDNA was extracted and analysed for KRAS mutations (mutKRAS) by digital droplet PCR. Nineteen patients displayed a mutKRAS in baseline plasma samples. There was a statistically significant difference in progression-free survival (PFS) and overall survival (OS) in patients with increase vs. stability/reduction of cftDNA in the sample collected at day 15 (median PFS 2.5 vs 7.5 months, p = 0.03; median OS 6.5 vs 11.5 months, p = 0.009). The results of this study demonstrate that cftDNA mutKRAS changes are associated with tumor response to chemotherapy and support the evidence that mutKRAS in plasma may be used as a new marker for monitoring treatment outcome and disease progression in PDAC

KRAS and BRAF genotyping of synchronous colorectal carcinomas.

Abstract. v‑Ki‑ras2 Kirsten rat sarcoma viral oncogene homolog (KRAS) genotyping is required prior to anti‑epidermal growth factor receptor monoclonal antibody therapy administered in cases of metastatic colorectal carcinoma (CRC). Thus, KRAS mutation screening is required for patient management. The present study reported the experience of KRAS/v‑raf murine sarcoma viral oncogene homolog B1 (BRAF) mutational screening on synchronous CRC pairs from 26 patients, which were defined as index lesions (ILs) and concurrent lesions (CLs) on the basis of tumor grade and dimension and their respective lymph node and distant metastases. Overall, KRAS mutations were present in 38.4% of patients, whereas BRAF mutations were present at a frequency of 11.5%. The genotyping of paired synchronous carcinomas indicated that 11 patients (42.3%) exhibited discordant KRAS mutational statuses in terms of the presence of a mutation in only one lesion of the pair or of two different mutations harbored by each lesion. BRAF mutations were present in the synchronous tumors of two cases, whereas in two other cases, only the IL or CL harbored mutant BRAF. Overall, the mutational statuses of distant and lymph node metastases confirm the genetic heterogeneity of synchronous primary tumors. These results highlighted the fact that adequate sampling and comprehensive testing, when feasible, is likely to optimize the decision‑making process for treatment approaches, even in the relatively rare event of multiple synchronous lesions

Initial therapy with FOLFOXIRI and bevacizumab for metastatic colorectal cancer

A fluoropyrimidine plus irinotecan or oxaliplatin, combined with bevacizumab (a monoclonal antibody against vascular endothelial growth factor), is standard first-line treatment for metastatic colorectal cancer. Before the introduction of bevacizumab, chemotherapy with fluorouracil, leucovorin, oxaliplatin, and irinotecan (FOLFOXIRI) showed superior efficacy as compared with fluorouracil, leucovorin, and irinotecan (FOLFIRI). In a phase 2 study, FOLFOXIRI plus bevacizumab showed promising activity and an acceptable rate of adverse effects