Abstract P1-20-04: Nanoformulation of doxorubicin inside H- ferritin nanocages allows a cardio-safe combined therapy with trastuzumab: De-escalating cardiotoxicity in HER2-positive breast cancer

Background: HER2+ breast cancer (BC) accounts for 20-25 % of BCs and it is characterized by high aggressiveness.1 Despite the anti-HER2 monoclonal antibody Trastuzumab (TZ) has improved BC clinical outcome, it could induce severe cardiac reversible dysfunction:2 HER2 signaling is also essential for growth and survival of myocardiocytes.3 Therefore, the concurrent use of TZ with other cardiotoxic drugs as doxorubicin (DOX) is discouraged.3 Both neoadjuvant and adjuvant clinical trials have challenged the notion that TZ should be administered with anthracyclines only sequentially,4 despite pre-clinical studies demonstrated the significant enhancement of efficacy by their coadministration.5-7 Nanomedicine answers to this clinical issue with HFn-DOX: a natural protein-based DOX nanoformulation with native tumor targeting capability that displays a self-triggered nuclear delivery of DOX improving antitumor efficacy and reducing both chemoresistance and cardiotoxicity.8

Methods: HER2+ BC bearing mice have been treated 5 times twice a week with placebo, HFn-DOX (1 mg/Kg, i.v.), TZ (5 mg/Kg, i.p.) and with the combination of them. Main end-point were cardiotoxicity and anticancer efficacy. Tumor size was measured by caliper, while antitumor activity and cardiotoxicity were characterized by ICH, immunofluorescence, cytofluorimetry, TEM, mass spectrometry and western blot on resections. Statistical analyses were conducted using two-tailed Student's t-test (P< 0.05)

Results: Although single treatments with HFn-DOX or TZ display a good capability to reduce tumor progression, their combination improves antitumor potential, affecting tumor size and angiogenesis. Since the main TZ activity is the induction of the Antibody-Dependent Cell mediated Cytotoxicity, we have assessed the effect of HFn-DOX on Tumor Infiltrating Lymphocytes (TIL), revealing that both TILs enumeration and TIL activity is unaffected by HFn-DOX. On the other hand, HFn-DOX increases the induction of apoptosis, suggesting that the reduction of the tumor size observed in mice treated with the combination of TZ and HFn-DOX is attributable to the coupling of these activity. Mitochondrial morphology has been checked for cardiotoxicity. A pathological increase in mitochondria area coupled with cristae depletion has been evidenced only in mice treated with TZ alone, confirming the overall safety of the HFn-DOX formulation. Interestingly, mice treated with the TZ and HFn-DOX did not display evidences of cardiac suffering. TZ quantification in tumor and heart revealed that the combination with HFn-DOX couples the increased TZ accumulation and penetration in tumor with TZ reduction in heart, resulting in the lack of cardiotoxicity.

Conclusions: Our results suggest that a combined therapy with HFn-DOX and TZ allows an enhanced anticancer activity and reduced cardiotoxicity, with potential translational implications on the treatment of HER2+ BC patients.

[1] Nat Rev Cancer 2009; 9:463; [2] Nat. Med. 2012; 18(11):1639; [3] Cancer treatments reviews 2009; 35:633; [4] The breast 2014; 23:317; [5] Cancer Res. 1998; 58(13):2825; [6] Lancet Oncol. 2011; 12(3):236; [7] Lancet 2010; 375(9712):377. [8] Oncotarget. 2017; 8:8383.

Citation Format: Mazzucchelli S, Andreata F, Bonizzi A, Monieri M, Bellini M, Longhi E, Ottria R, Sorrentino L, Truffi M, Prosperi D, Zerbi P, Corsi F. Nanoformulation of doxorubicin inside H- ferritin nanocages allows a cardio-safe combined therapy with trastuzumab: De-escalating cardiotoxicity in HER2-positive breast cancer [abstract]. In: Proceedings of the 2018 San Antonio Breast Cancer Symposium; 2018 Dec 4-8; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2019;79(4 Suppl):Abstract nr P1-20-04.

Abstract P1-10-13: Olaparib nanoformulation in H-ferritin as a promising option for both BRCA-mutated and sporadic triple negative breast cancer: An in vitro study

Background: PolyADP-ribose polymerase (PARP) inhibitors are a novel promising strategy toward triple-negative breast cancer (TNBC), which often shows genomic instability or BRCA mutations. However, clinical results are controversial, and no benefits were demonstrated in case of wild type BRCA, possibly due to poor bioavailability, and inadequate nuclear delivery. Nanotechnology could overcome these major limitations. The aim of this study was to assess the anticancer efficacy of H-Ferritin nanoformulated Olaparib (HOla) vs. free Olaparib (Ola) on BRCA-mutated and non mutated TNBC cells.

Methods: BRCA-mutated HCC1937 cells and BRCA-wild type MDA MB-231 and MDA MB-468 cells were treated with HOla or free Ola in vitro. Active targeting and binding capability of HOla toward transferrin receptor 1 (TfR-1), over-expressed on TNBC cells, was assessed by flow cytometry. Internalization and intracellular localization of Ola and HOla was assessed by confocal microscopy. Anticancer efficacy was assessed by administration of increasing doses of HOla or Ola, comparing cell viability, cell cycle, cell death, PARP-1 cleavage and DNA damage. Finally, anti-PARP efficacy and proportion of drug in the nuclear compartment were compared between treatments.

Results: All TNBC cell lines over-expressed TfR-1 and were succesfully recognized by HOla. Confocal microscopy showed a fast internalization of nanoparticles into cells, with intracellular persistence up to 48h. A marked increase in nuclear concentration of drug was observed with HOla compared to Ola, due to a strongly improved nuclear delivery by H-Ferritin mediated by a self-triggered mechanism. No significant antiproliferative effect was demonstrated with Ola at 10 nM, 50 nM or 100 nM. Conversely, HOla at 50 nM and 100 nM showed a 1000-fold higher anticancer activity in all TNBC cell lines. A possible contribution in cytotoxicity by H-Ferritin nanovector itself was excluded treating cells with void nanoparticles. Proportions of cell cycle arrest in G2/M, cell death, cleaved PARP-1 and DNA damage in terms of phosphorylated histone H2A.X were higher in HOla treated samples than in ones treated with free Ola.

Conclusions:Our findings suggest that nanoformulation of Ola strongly enhances cytotoxic efficacy of PARP inhibition as a stand-alone therapy, on both BRCA-mutated and wild type TNBCs allowing a targeted delivery into TNBC cells and a prompt homing into the nuclear compartment.

Citation Format: Mazzucchelli S, Truffi M, Sorrentino L, Bellini M, Rizzuto MA, Ottria R, Ciuffreda P, Prosperi D, Corsi F. Olaparib nanoformulation in H-ferritin as a promising option for both BRCA-mutated and sporadic triple negative breast cancer: An in vitro study [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P1-10-13.

Plasma endocannabinoid behaviour in total knee and hip arthroplasty

Endocannabinoids are a class of lipid mediators involved in a wide range of physiological pathways including pain perception, and immunological defences. In particular, the involvement of endocannabinoids in bone metabolism and bone resorption has recently been studied. Moreover, one study on total knee arthroplasty describes the probable role of endocannabinoids in pain perception after surgery. The aim of the present study was to evaluate variations of endocannabinoid concentrations in patients undergoing total hip or total knee arthroplasty before and after surgery. Sera from 23 patients were collected at three different times: before surgery and at two different times during rehabilitation, and endocannabinoids were quantified by HPLC-MS/MS analysis. Mean values of endocannabinoids in presurgical serum samples were: 6.11±0.5 ng/ml for N-palmitoylethanolamide, 1.39±0.08ng/ml for N-stearoylethanolamide, 4.84±0.04 ng/ml for N-oleoylethanolamide, 0.44±0.03ng/ml for N-arachidonoylethanolamide, 0.84±0.05ng/ml for N-linoleoylethanolamide, 0.17±0.01ng/ml for N-α-linolenoylethanolamide. Statistical analysis showed a significant decrease of all the endocannabinoids after surgery, while there were no remarkable differences between total hip and total knee arthroplasties or between genders. Moreover, the results show no significant correlation between endocannabinoid concentrations and C-reactive protein and Erythrocyte sedimentation rate. The present study shows for the first time a specific and univocal behaviour of six endocannabinoids and N-acylethanolamides in orthopaedic surgery, suggesting the endocannabinoid system as a possible pharmacological target for presurgical therapeutics.

Effects of bioactive fatty acid amide derivatives in zebrafish scale model of bone metabolism and disease

The endocannabinoid system (which includes fatty acid derivatives, receptors, and metabolizing enzymes) is involved in a variety of physiological processes, including bone metabolism in which it regulates the function of osteoblasts and osteoclasts, as well as differentiation of their precursors. The zebrafish (Danio rerio) provides a useful animal model for bone research since zebrafish bones develop rapidly and are anatomically similar to mammalian bones. Putative orthologues and paralogs of endocannabinoid genes have recently been identified in zebrafish, demonstrating the presence of cannabinoid type 1 (CB1) and type 2 (CB2) receptors with affinity to endocannabinoid ligands. To identify therapeutic molecules potentially useful in bone-related diseases, we evaluated the in vivo effects of exposure to long-chain fatty acid amides in adult zebrafish. Using a well-established zebrafish scale model, we found that anandamide and N-linoleoylethanolamine are able to stimulate bone formation by increasing alkaline phosphatase activity in physiological conditions. In addition, they prevent the alteration of bone markers in a prednisolone-induced osteoporosis model in adult zebrafish scales, whereas their esterified forms do not. These data suggest that long-chain fatty acid amides are involved in regulating bone metabolism in zebrafish scales and that the CB2 receptor is a key mediator in this process.