Invasive lobular carcinoma (ILC) is the second most common subtype of breast cancer after invasive breast cancer of no special type (IBC-NST). This retrospective analysis of the MINDACT trial investig Show more
Invasive lobular carcinoma (ILC) is the second most common subtype of breast cancer after invasive breast cancer of no special type (IBC-NST). This retrospective analysis of the MINDACT trial investigated transcriptomic differences between estrogen receptor-positive/HER2-negative (ER+/HER2-) ILC versus ER+/HER2- IBC-NST, classic and non-classic ER+/HER2- ILC, and, recurring and non-recurring ER+/HER2- ILC in patients with a low genomic risk and either a low (cL/gL) or high clinical risk (cH/gL). We analyzed 4261 ER+/HER2- tumors (63.7%, 464 ILC, 3798 IBC-NST) with central pathology review. Differential gene expression analysis was adjusted for age and grade, followed by gene set enrichment analysis. Adjusted regression models evaluated associations of transcriptomic profiles with disease-free (DFS) and distant recurrence-free survival (DRFS). An increased expression of CDH1 (E-cadherin) in IBC-NST compared to ILC was observed. ILC showed more uptake of extracellular lipid sources (LPL, CD36, LEP, LEPR), while IBC-NST favored lipid synthesis (FASN). Decreased ER-signaling, increased PI3K/Akt-signaling, and differences related to the extracellular matrix was also observed in ILC. Classic and non-classic ILC differed subtly, notably in cell cycle regulation. In ER+/HER2- ILC patients with a cL/gL risk, enrichment of apoptosis, inflammatory response, hypoxia and oncogenic signaling (PI3K/Akt, Ras, c-Myc) was associated with worse survival. In contrast, in the cH/gL group, associations between ILC transcriptomic features and survival were more subtle. This represents the largest transcriptomic dataset for ILC from a clinical trial with central histology review. Findings may provide insights to refine treatment and relapse risk assessment for ILC patients. Show less
The melanocortin 4 receptor (MC4R) plays a role in energy homeostasis and represents a target for treating energy balance disorders. For decades, synthetic ligands have been derived from MC4R endogeno Show more
The melanocortin 4 receptor (MC4R) plays a role in energy homeostasis and represents a target for treating energy balance disorders. For decades, synthetic ligands have been derived from MC4R endogenous agonists and antagonists, such as setmelanotide used to treat rare forms of genetic obesity. Recently, animal venoms have demonstrated their capacity to provide melanocortin ligands with toxins from a scorpion and a spider. Here, we described a cone snail toxin, N-CTX-Ltg1a, with a nanomolar affinity for hMC4R but unrelated to any known toxins or melanocortin ligands. We then derived from the conotoxin the linear peptide HT1-0, a competitive antagonist of Show less