PAM50 Intrinsic Subtype Profiles in Primary and Metastatic Breast Cancer Show a Significant Shift toward More Aggressive Subtypes with Prognostic Implications.

BACKGROUND: PAM50 breast cancer intrinsic subtyping adds prognostic information in early breast cancer; however, the role in metastatic disease is unclear. We aimed to identify PAM50 subtypes in primary tumors (PTs) and metastases to outline subtype changes and their prognostic role. METHODS: RNA was isolated from PTs, lymph node metastases (LNMs), and distant metastases (DMs) in metastatic breast cancer patients (n = 140) included in a prospective study (NCT01322893). Gene expression analyses were performed using the Breast Cancer 360 (BC360) assay from Nano-String. The subtype shifts were evaluated using McNemar and symmetry tests, and clinical outcomes were evaluated with log-rank tests and Cox regression. RESULTS: The PAM50 subtype changed in 25/59 of paired samples between PTs and LNMs (Psymmetry = 0.002), in 31/61 between PTs and DMs (Psymmetry < 0.001), and in 16/38 between LNMs and DMs (Psymmetry = 0.004). Shifts toward subtypes with worse outcomes were the most common. Patients with shifts from the luminal PT to non-luminal DM subtypes had worse progression-free survival compared to patients with a stable subtype (hazard ratio (HR): 2.3; 95% confidence interval (CI): 1.14-4.68, p = 0.02). CONCLUSION: Strong evidence of PAM50 subtype shifts toward unfavorable subtypes were seen between PTs and metastatic samples. For patients with a shift in subtype from luminal PT to non-luminal DM, a worse prognosis was noted.

TILs Immunophenotype in Breast Cancer Predicts Local Failure and Overall Survival: Analysis in a Large Radiotherapy Trial with Long-Term Follow-Up.

AIM: To determine the prognostic significance of the immunophenotype of tumour-infiltrating lymphocytes (TILs) within a cohort of breast cancer patients with long-term follow-up. METHODS: Multiplexed immunofluorescence and automated image analysis were used to assess the expression of CD3, CD8, CD20, CD68, Fox P3, PD-1 and PD-L1 in a clinical trial of local excision and radiotherapy randomised to a cavity boost or not (n = 485, median follow-up 16 years). Kaplan-Meier and Cox multivariate analysis (MVA) methodology were used to ascertain relationships with local recurrence (LR), overall survival (OS) and disease-free survival (DFS). NanoString BC360 gene expression panel was applied to a subset of luminal patients to identify pathways associated with LR. RESULTS: LR was predicted by low CD8 in MVA in the whole cohort (HR 2.34, CI 1.4-4.02, p = 0.002) and luminal tumours (HR 2.19, CI 1.23-3.92, p = 0.008) with associations with increased stromal components, decreased Tregs (FoxP3), inflammatory chemokines and SOX2. Poor OS was associated with low CD20 in the whole cohort (HR 1.73, CI 1.2-2.4, p = 0.002) and luminal tumours on MVA and low PD-L1 in triple-negative cancer (HR 3.44, CI 1.5-7, p = 0.003). CONCLUSIONS: Immunophenotype adds further prognostic data to help further stratify risk of LR and OS even in TILs low-luminal tumours.

Axon degeneration induces glial responses through Draper-TRAF4-JNK signalling.

Draper/Ced-1/MEGF-10 is an engulfment receptor that promotes clearance of cellular debris in C. elegans, Drosophila and mammals. Draper signals through an evolutionarily conserved Src family kinase cascade to drive cytoskeletal rearrangements and target engulfment through Rac1. Glia also alter gene expression patterns in response to axonal injury but pathways mediating these responses are poorly defined. We show Draper is cell autonomously required for glial activation of transcriptional reporters after axonal injury. We identify TNF receptor associated factor 4 (TRAF4) as a novel Draper binding partner that is required for reporter activation and phagocytosis of axonal debris. TRAF4 and misshapen (MSN) act downstream of Draper to activate c-Jun N-terminal kinase (JNK) signalling in glia, resulting in changes in transcriptional reporters that are dependent on Drosophila AP-1 (dAP-1) and STAT92E. Our data argue injury signals received by Draper at the membrane are important regulators of downstream transcriptional responses in reactive glia.

PI3K signaling and Stat92E converge to modulate glial responsiveness to axonal injury.

Glial cells are exquisitely sensitive to neuronal injury but mechanisms by which glia establish competence to respond to injury, continuously gauge neuronal health, and rapidly activate reactive responses remain poorly defined. Here, we show glial PI3K signaling in the uninjured brain regulates baseline levels of Draper, a receptor essential for Drosophila glia to sense and respond to axonal injury. After injury, Draper levels are up-regulated through a Stat92E-modulated, injury-responsive enhancer element within the draper gene. Surprisingly, canonical JAK/STAT signaling does not regulate draper expression. Rather, we find injury-induced draper activation is downstream of the Draper/Src42a/Shark/Rac1 engulfment signaling pathway. Thus, PI3K signaling and Stat92E are critical in vivo regulators of glial responsiveness to axonal injury. We provide evidence for a positive auto-regulatory mechanism whereby signaling through the injury-responsive Draper receptor leads to Stat92E-dependent, transcriptional activation of the draper gene. We propose that Drosophila glia use this auto-regulatory loop as a mechanism to adjust their reactive state following injury.