JAK2 and PD-L1 Amplification Enhance the Dynamic Expression of PD-L1 in Triple-negative Breast Cancer

Meixuan Chen, Barbara Pockaj, Mariacarla Andreozzi, Michael T. Barrett, Sri Krishna, Seron Eaton, Ruifang Niu, Karen Anderson

    Research output: Contribution to journalArticle

    3 Citations (Scopus)

    Abstract

    The present study evaluated the interaction between the JAK2 and programmed cell death ligand 1 (PD-L1) pathways in triple-negative breast cancer (TNBC). A subset of TNBC tumors had a 9p24.1 amplification encoding JAK2 and PD-L1. We observed a synergy between the JAK2/interferon-γ pathway and 9p24.1 amplification, leading to increased PD-L1 expression. Background: Activation of the JAK/STAT pathway is common in triple-negative breast cancer (TNBC) and affects the expression of genes controlling immune signaling. A subset of TNBC cases will have somatic amplification of chromosome 9p24.1, encoding PD-L1, PD-L2, and JAK2, which has been associated with decreased survival. Materials and Methods: Eleven TNBC cell lines were evaluated using array comparative genomic hybridization. A copy number gain was defined as an array comparative genomic hybridization log2 ratio of ≥ 1. Cell surface expression of programmed cell death ligand 1 (PD-L1) was detected using flow cytometry and compared with the median fluorescence intensity of isotype control immunoglobulin. To selectively inhibit JAK2, lentiviral vectors encoding 2 different short hairpin RNA (shRNA) were generated. JAK2, STAT1, STAT3, phosphorylated (p) STAT1, and pSTAT3 expression were measured by immunoblot. Statistical significance was defined as P < .05. Results: The cell line HCC70 had 9p24.1 copy number amplification that was associated with both increased JAK2 and pSTAT3; however, knockdown of JAK2 inhibited cell growth independently of 9p24.1 copy number status. In TNBC cell lines with 9p24.1 gain or amplification, PD-L1 expression rapidly and strikingly increased 5- to 38-fold with interferon-γ (P < .05), and inducible PD-L1 expression was completely blocked by JAK2 knockdown and the JAK1/2 inhibitor ruxolitinib. In tumor tissue, expression of interferon-γ–related genes correlated with 9p24.1 copy number status. Conclusion: These data suggest that the JAK2/STAT1 pathway in TNBC might regulate the dynamic expression of PD-L1 that is induced in the setting of an inflammatory response. Inhibition of JAK2 might provide a synergistic therapy when combined with other immunotherapies in the subset of TNBC with 9p24.1 amplification.

    Original languageEnglish (US)
    JournalClinical Breast Cancer
    DOIs
    StateAccepted/In press - Jan 1 2018

    Fingerprint

    Triple Negative Breast Neoplasms
    Cell Death
    Ligands
    Interferons
    Comparative Genomic Hybridization
    Programmed Cell Death 1 Ligand 2 Protein
    Cell Line
    Immunoglobulin Isotypes
    Immunotherapy
    Small Interfering RNA
    Flow Cytometry
    Chromosomes
    Fluorescence
    Breast Neoplasms
    Gene Expression

    Keywords

    • Biomarker
    • Checkpoint blockade
    • Immunotherapy
    • Programmed cell death ligand 1
    • TNBC

    ASJC Scopus subject areas

    • Oncology
    • Cancer Research

    Cite this

    JAK2 and PD-L1 Amplification Enhance the Dynamic Expression of PD-L1 in Triple-negative Breast Cancer. / Chen, Meixuan; Pockaj, Barbara; Andreozzi, Mariacarla; Barrett, Michael T.; Krishna, Sri; Eaton, Seron; Niu, Ruifang; Anderson, Karen.

    In: Clinical Breast Cancer, 01.01.2018.

    Research output: Contribution to journalArticle

    Chen, Meixuan ; Pockaj, Barbara ; Andreozzi, Mariacarla ; Barrett, Michael T. ; Krishna, Sri ; Eaton, Seron ; Niu, Ruifang ; Anderson, Karen. / JAK2 and PD-L1 Amplification Enhance the Dynamic Expression of PD-L1 in Triple-negative Breast Cancer. In: Clinical Breast Cancer. 2018.
    @article{a8968085ec8745469cf51f91b0a0ceaa,
    title = "JAK2 and PD-L1 Amplification Enhance the Dynamic Expression of PD-L1 in Triple-negative Breast Cancer",
    abstract = "The present study evaluated the interaction between the JAK2 and programmed cell death ligand 1 (PD-L1) pathways in triple-negative breast cancer (TNBC). A subset of TNBC tumors had a 9p24.1 amplification encoding JAK2 and PD-L1. We observed a synergy between the JAK2/interferon-γ pathway and 9p24.1 amplification, leading to increased PD-L1 expression. Background: Activation of the JAK/STAT pathway is common in triple-negative breast cancer (TNBC) and affects the expression of genes controlling immune signaling. A subset of TNBC cases will have somatic amplification of chromosome 9p24.1, encoding PD-L1, PD-L2, and JAK2, which has been associated with decreased survival. Materials and Methods: Eleven TNBC cell lines were evaluated using array comparative genomic hybridization. A copy number gain was defined as an array comparative genomic hybridization log2 ratio of ≥ 1. Cell surface expression of programmed cell death ligand 1 (PD-L1) was detected using flow cytometry and compared with the median fluorescence intensity of isotype control immunoglobulin. To selectively inhibit JAK2, lentiviral vectors encoding 2 different short hairpin RNA (shRNA) were generated. JAK2, STAT1, STAT3, phosphorylated (p) STAT1, and pSTAT3 expression were measured by immunoblot. Statistical significance was defined as P < .05. Results: The cell line HCC70 had 9p24.1 copy number amplification that was associated with both increased JAK2 and pSTAT3; however, knockdown of JAK2 inhibited cell growth independently of 9p24.1 copy number status. In TNBC cell lines with 9p24.1 gain or amplification, PD-L1 expression rapidly and strikingly increased 5- to 38-fold with interferon-γ (P < .05), and inducible PD-L1 expression was completely blocked by JAK2 knockdown and the JAK1/2 inhibitor ruxolitinib. In tumor tissue, expression of interferon-γ–related genes correlated with 9p24.1 copy number status. Conclusion: These data suggest that the JAK2/STAT1 pathway in TNBC might regulate the dynamic expression of PD-L1 that is induced in the setting of an inflammatory response. Inhibition of JAK2 might provide a synergistic therapy when combined with other immunotherapies in the subset of TNBC with 9p24.1 amplification.",
    keywords = "Biomarker, Checkpoint blockade, Immunotherapy, Programmed cell death ligand 1, TNBC",
    author = "Meixuan Chen and Barbara Pockaj and Mariacarla Andreozzi and Barrett, {Michael T.} and Sri Krishna and Seron Eaton and Ruifang Niu and Karen Anderson",
    year = "2018",
    month = "1",
    day = "1",
    doi = "10.1016/j.clbc.2018.05.006",
    language = "English (US)",
    journal = "Clinical Breast Cancer",
    issn = "1526-8209",
    publisher = "Elsevier",

    }

    TY - JOUR

    T1 - JAK2 and PD-L1 Amplification Enhance the Dynamic Expression of PD-L1 in Triple-negative Breast Cancer

    AU - Chen, Meixuan

    AU - Pockaj, Barbara

    AU - Andreozzi, Mariacarla

    AU - Barrett, Michael T.

    AU - Krishna, Sri

    AU - Eaton, Seron

    AU - Niu, Ruifang

    AU - Anderson, Karen

    PY - 2018/1/1

    Y1 - 2018/1/1

    N2 - The present study evaluated the interaction between the JAK2 and programmed cell death ligand 1 (PD-L1) pathways in triple-negative breast cancer (TNBC). A subset of TNBC tumors had a 9p24.1 amplification encoding JAK2 and PD-L1. We observed a synergy between the JAK2/interferon-γ pathway and 9p24.1 amplification, leading to increased PD-L1 expression. Background: Activation of the JAK/STAT pathway is common in triple-negative breast cancer (TNBC) and affects the expression of genes controlling immune signaling. A subset of TNBC cases will have somatic amplification of chromosome 9p24.1, encoding PD-L1, PD-L2, and JAK2, which has been associated with decreased survival. Materials and Methods: Eleven TNBC cell lines were evaluated using array comparative genomic hybridization. A copy number gain was defined as an array comparative genomic hybridization log2 ratio of ≥ 1. Cell surface expression of programmed cell death ligand 1 (PD-L1) was detected using flow cytometry and compared with the median fluorescence intensity of isotype control immunoglobulin. To selectively inhibit JAK2, lentiviral vectors encoding 2 different short hairpin RNA (shRNA) were generated. JAK2, STAT1, STAT3, phosphorylated (p) STAT1, and pSTAT3 expression were measured by immunoblot. Statistical significance was defined as P < .05. Results: The cell line HCC70 had 9p24.1 copy number amplification that was associated with both increased JAK2 and pSTAT3; however, knockdown of JAK2 inhibited cell growth independently of 9p24.1 copy number status. In TNBC cell lines with 9p24.1 gain or amplification, PD-L1 expression rapidly and strikingly increased 5- to 38-fold with interferon-γ (P < .05), and inducible PD-L1 expression was completely blocked by JAK2 knockdown and the JAK1/2 inhibitor ruxolitinib. In tumor tissue, expression of interferon-γ–related genes correlated with 9p24.1 copy number status. Conclusion: These data suggest that the JAK2/STAT1 pathway in TNBC might regulate the dynamic expression of PD-L1 that is induced in the setting of an inflammatory response. Inhibition of JAK2 might provide a synergistic therapy when combined with other immunotherapies in the subset of TNBC with 9p24.1 amplification.

    AB - The present study evaluated the interaction between the JAK2 and programmed cell death ligand 1 (PD-L1) pathways in triple-negative breast cancer (TNBC). A subset of TNBC tumors had a 9p24.1 amplification encoding JAK2 and PD-L1. We observed a synergy between the JAK2/interferon-γ pathway and 9p24.1 amplification, leading to increased PD-L1 expression. Background: Activation of the JAK/STAT pathway is common in triple-negative breast cancer (TNBC) and affects the expression of genes controlling immune signaling. A subset of TNBC cases will have somatic amplification of chromosome 9p24.1, encoding PD-L1, PD-L2, and JAK2, which has been associated with decreased survival. Materials and Methods: Eleven TNBC cell lines were evaluated using array comparative genomic hybridization. A copy number gain was defined as an array comparative genomic hybridization log2 ratio of ≥ 1. Cell surface expression of programmed cell death ligand 1 (PD-L1) was detected using flow cytometry and compared with the median fluorescence intensity of isotype control immunoglobulin. To selectively inhibit JAK2, lentiviral vectors encoding 2 different short hairpin RNA (shRNA) were generated. JAK2, STAT1, STAT3, phosphorylated (p) STAT1, and pSTAT3 expression were measured by immunoblot. Statistical significance was defined as P < .05. Results: The cell line HCC70 had 9p24.1 copy number amplification that was associated with both increased JAK2 and pSTAT3; however, knockdown of JAK2 inhibited cell growth independently of 9p24.1 copy number status. In TNBC cell lines with 9p24.1 gain or amplification, PD-L1 expression rapidly and strikingly increased 5- to 38-fold with interferon-γ (P < .05), and inducible PD-L1 expression was completely blocked by JAK2 knockdown and the JAK1/2 inhibitor ruxolitinib. In tumor tissue, expression of interferon-γ–related genes correlated with 9p24.1 copy number status. Conclusion: These data suggest that the JAK2/STAT1 pathway in TNBC might regulate the dynamic expression of PD-L1 that is induced in the setting of an inflammatory response. Inhibition of JAK2 might provide a synergistic therapy when combined with other immunotherapies in the subset of TNBC with 9p24.1 amplification.

    KW - Biomarker

    KW - Checkpoint blockade

    KW - Immunotherapy

    KW - Programmed cell death ligand 1

    KW - TNBC

    UR - http://www.scopus.com/inward/record.url?scp=85048775557&partnerID=8YFLogxK

    UR - http://www.scopus.com/inward/citedby.url?scp=85048775557&partnerID=8YFLogxK

    U2 - 10.1016/j.clbc.2018.05.006

    DO - 10.1016/j.clbc.2018.05.006

    M3 - Article

    JO - Clinical Breast Cancer

    JF - Clinical Breast Cancer

    SN - 1526-8209

    ER -