Cancer immunotherapies, such as atezolizumab, are proving to be a valuable therapeutic strategy across indications, including non-small cell lung cancer (NSCLC) and urothelial cancer (UC). Here, we describe a diagnostic assay that measures programmed-death ligand 1 (PD-L1) expression, via immunohistochemistry, to identify patients who will derive the most benefit from treatment with atezolizumab, a humanized monoclonal anti-PD-L1 antibody. We describe the performance of the VENTANA PD-L1 (SP142) Assay in terms of specificity, sensitivity, and the ability to stain both tumor cells (TC) and tumor-infiltrating immune cells (IC), in NSCLC and UC tissues. The reader precision, repeatability and intermediate precision, interlaboratory reproducibility, and the effectiveness of pathologist training on the assessment of PD-L1 staining on both TC and IC were evaluated. We detail the analytical validation of the VENTANA PD-L1 (SP142) Assay for PD-L1 expression in NSCLC and UC tissues and show that the assay reliably evaluated staining on both TC and IC across multiple expression levels/clinical cut-offs. The reader precision showed high overall agreement when compared with consensus scores. In addition, pathologists met the predefined training criteria (≥85.0% overall percent agreement) for the assessment of PD-L1 expression in NSCLC and UC tissues with an average overall percent agreement ≥95.0%. The assay evaluates PD-L1 staining on both cell types and is robust and precise. In addition, it can help to identify those patients who may benefit the most from treatment with atezolizumab, although treatment benefit has been demonstrated in an all-comer NSCLC and UC patient population.This is an open-access article distributed under the terms of the Creative Commons Attribution-Non Commercial-No Derivatives License 4.0 (CCBY-NC-ND), where it is permissible to download and share the work provided it is properly cited. The work cannot be changed in any way or used commercially without permission from the journal. http://creativecommons.org/licenses/by-nc-nd/4.0/.
BackgroundPrimary cilia are microtubule-based organelles that protrude from the cell surface. Primary cilia play a critical role in development and disease through regulation of signaling pathways including the Hedgehog pathway. Recent mouse models have also linked ciliary dysfunction to cancer. However, little is known about the role of primary cilia in breast cancer development. Primary cilia expression was characterized in cancer cells as well as their surrounding stromal cells from 86 breast cancer patients by counting cilia and measuring cilia length. In addition, we examined cilia expression in normal epithelial and stromal cells from reduction mammoplasties as well as histologically normal adjacent tissue for comparison.ResultsWe observed a statistically significant decrease in the percentage of ciliated cells on both premalignant lesions as well as in invasive cancers. This loss of cilia does not correlate with increased proliferative index (Ki67-positive cells). However, we did detect rare ciliated cancer cells present in patients with invasive breast cancer and found that these express a marker of basaloid cancers that is associated with poor prognosis (Cytokeratin 5). Interestingly, the percentage of ciliated stromal cells associated with both premalignant and invasive cancers decreased when compared to stromal cells associated with normal tissue. To understand how cilia may be lost during cancer development we analyzed the expression of genes required for ciliogenesis and/or ciliary function and compared their expression in normal versus breast cancer samples. We found that expression of ciliary genes were frequently downregulated in human breast cancers.ConclusionsThese data suggest that primary cilia are lost early in breast cancer development on both the cancer cells and their surrounding stromal cells.
Purpose: During cancer progression, the oncoprotein MUC1 binds h-catenin while simultaneously inhibiting the degradation of the epidermal growth factor receptor (EGFR), resulting in enhanced transformation and metastasis. The purpose of this study was to design a peptidebased therapy that would block these intracellular protein-protein interactions as a treatment for metastatic breast cancer. Experimental Design: The amino acid residues responsible for these interactions lie in tandem in the cytoplasmic domain of MUC1, and we have targeted this sequence to produce a MUC1 peptide that blocks the protumorigenic functions of MUC1. We designed the MUC1 inhibitory peptide (MIP) to block the intracellular interactions between MUC1/h-catenin and MUC1/EGFR. To allow for cellular uptake we synthesized MIP adjacent to the protein transduction domain, PTD4 (PMIP). Results: We have found that PMIP acts in a dominant-negative fashion, blocking both MUC1/hcatenin and MUC1/EGFR interactions. In addition, PMIP induces ligand-dependent reduction of EGFR levels. These effects correspond to a significant reduction in proliferation, migration, and invasion of metastatic breast cancer cells in vitro, and inhibition of tumor growth and recurrence in an established MDA-MB-231 immunocompromised (SCID) mouse model. Importantly, PMIP also inhibits genetically driven breast cancer progression, as injection of tumor-bearing MMTV-pyV mT transgenic mice with PMIP results in tumor regression and a significant inhibition of tumor growth rate. Conclusions: These data show that intracellular MUC1 peptides possess significant antitumor activity and have important clinical applications in the treatment of cancer.MUC1 (DF3, CD227, episialin, PEM) is a heavily Oglycosylated heterodimeric protein of >300 kDa, normally expressed abundantly on the apical surface of glandular epithelia. In more than 90% of human breast carcinomas and metastases, apical localization is lost and MUC1 is overexpressed (by >10-fold) and underglycosylated (1, 2). Deregulated expression of MUC1 is found in many other types of adenocarcinomas as well, including cancers of the lung, pancreas, ovary, and prostate, in addition to being highly expressed in leukemias, myelomas, and lymphomas (3 -5). Studies in both genetic mouse models and cell line models have shown that MUC1 is an oncogene. A transgenic mouse model driving MUC1 (human) overexpression to the mouse mammary gland (MMTV-MUC1) results in the development of breast cancer and is accompanied by a failure of the mammary gland to undergo complete postlactational regression via apoptosis (6). Transfection of MUC1 into 3Y1 fibroblasts induces their transformation, and transfection of MUC1 into colon cancer cells shows that MUC1 overexpression inhibits drug-induced apoptosis (7).The cytoplasmic domain of MUC1 contains sites for multiple protein interactions, although these interactions go largely unformed in the polarized epithelium of the normal breast, as the binding partners of MUC1 are typically found on the baso...
Context.— The ability to determine ROS1 status has become mandatory for patients with lung adenocarcinoma, as many global authorities have approved crizotinib for patients with ROS1-positive lung adenocarcinoma. Objective.— To present analytical correlation of the VENTANA ROS1 (SP384) Rabbit Monoclonal Primary Antibody (ROS1 [SP384] antibody) with ROS1 fluorescence in situ hybridization (FISH). Design.— The immunohistochemistry (IHC) and FISH analytical comparison was assessed by using 122 non–small cell lung cancer samples that had both FISH (46 positive and 76 negative cases) and IHC staining results available. In addition, reverse transcription–polymerase chain reaction (RT-PCR) as well as DNA and RNA next-generation sequencing (NGS) were used to further examine the ROS1 status in cases that were discrepant between FISH and IHC, based on staining in the cytoplasm of 2+ or above in more than 30% of total tumor cells considered as IHC positive. Here, we define the consensus status as the most frequent result across the 5 different methods (IHC, FISH, RT-PCR, RNA NGS, and DNA NGS) we used to determine ROS1 status in these cases. Results.— Of the IHC scoring methods examined, staining in the cytoplasm of 2+ or above in more than 30% of total tumor cells considered as IHC positive had the highest correlation with a FISH-positive status, reaching a positive percentage agreement of 97.8% and negative percentage agreement of 89.5%. A positive percentage agreement (100%) and negative percentage agreement (92.0%) was reached by comparing ROS1 (SP384) using a cutoff for staining in the cytoplasm of 2+ or above in more than 30% of total tumor cells to the consensus status. Conclusions.— Herein, we present a standardized staining protocol for ROS1 (SP384) and data that support the high correlation between ROS1 status and ROS1 (SP384) antibody.
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