Combinatorial clinical trials of PARP inhibitors with immunotherapies are ongoing, yet the immunomodulatory effects of PARP inhibition have been incompletely studied. Here, we sought to dissect the mechanisms underlying PARP inhibitor-induced changes in the tumor microenvironment of BRCA1-defi cient triple-negative breast cancer (TNBC). We demonstrate that the PARP inhibitor olaparib induces CD8 + T-cell infi ltration and activation in vivo , and that CD8 + T-cell depletion severely compromises antitumor effi cacy. Olaparib-induced T-cell recruitment is mediated through activation of the cGAS/STING pathway in tumor cells with paracrine activation of dendritic cells and is more pronounced in HR-defi cient compared with HR-profi cient TNBC cells and in vivo models. CRISPR-mediated knockout of STING in cancer cells prevents proinfl ammatory signaling and is suffi cient to abolish olaparib-induced T-cell infi ltration in vivo. These fi ndings elucidate an additional mechanism of action of PARP inhibitors and provide a rationale for combining PARP inhibition with immunotherapies for the treatment of TNBC. SIGNIFICANCE: This work demonstrates cross-talk between PARP inhibition and the tumor microenvironment related to STING/TBK1/IRF3 pathway activation in cancer cells that governs CD8 + T-cell recruitment and antitumor effi cacy. The data provide insight into the mechanism of action of PARP inhibitors in BRCA-associated breast cancer.

Silymarin, the standardized extract of Silybum marianum, is used as a hepatoprotector in man, and is a potent antihepatotoxic agent. This study focused on the effects of a silymarin-phospholipid complex in reducing the toxic effects of aflatoxin B1 (AFB1) in broiler chickens. Twenty-one 14-d-old male commercial broilers were randomly allotted to 3 groups and treated as follows: basal diet alone [Group C (Control)]; AFB1 at 0.8 mg/kg of feed [Group B1]; AFB1 at 0.8 mg/kg of feed plus silymarin phytosome, a silymarin complexed form with phospholipids from soy, at 600 mg/kg of BW [Group B1+Sil]. Considering the whole growth cycle, BW gain and feed intake were lower in AFB1-treated birds with respect to controls (P < 0.05). In the B1+Sil group, BW gain and feed intake were higher with respect to birds receiving AFB1 alone (P < 0.05), and not different from the control birds. Serum biochemistry showed no difference among groups, except for a decrease of alanine amino transferase (ALT) in chicks treated only with AFB1. Alanine amino transferase activity in AFB1 plus silymarin phytosome treated birds was not different from the controls. No treatment differences were noted on liver weight. In conclusion, our results suggest that silymarin phytosome can provide protection against the negative effects of AFB1 on performance of broiler chicks.

The contribution of basal and luminal cells to cancer progression and metastasis is poorly understood. We report generation of reporter systems driven by either keratin-14 (K14) or keratin-8 (K8) promoter that not only express a fluorescent protein but also an inducible suicide gene. Transgenic mice express the reporter genes in the right cell compartments of mammary gland epithelia and respond to treatment with toxins. In addition, we engineered the reporters into 4T1 metastatic mouse tumor cell line and demonstrate that K14+ cells, but not K14− or K8+, are both highly invasive in three-dimensional (3D) culture and metastatic in vivo. Treatment of cells in culture, or tumors in mice, with reporter-targeting toxin inhibited both invasive behavior and metastasis in vivo. RNA sequencing (RNA-seq), secretome, and epigenome analysis of K14+ and K14− cells led to the identification of amphoterin-induced protein 2 (Amigo2) as a new cell invasion driver whose expression correlated with decreased relapse-free survival in patients with TP53 wild-type (WT) breast cancer.

No abstract

No abstract

No abstract

No abstract

No abstract