title: Gene expression profiling of anti-CTLA4-treated metastatic melanoma in patients with treatment-induced autoimmunity.
abstract: Ipilimumab (IPI) is a monoclonal antibody that targets the inhibitory CTLA4 receptor of T cells, enhancing T-cell-driven antitumor responses. IPI therapy in metastatic melanoma results in significant improvement in disease-free and overall survival, although after initial responses disease progression generally ensues. Identification of specific responses in tissue where melanoma tumor cells are subjected to IPI-driven immune attack may reveal mechanisms of treatment efficacy or resistance, permitting refinement of targeted therapeutic approaches. We used NanoString digital barcoding chemistry to identify changes in the transcriptome of metastatic melanoma cells before and after IPI treatment using two comprehensive panels containing a total of 1330 unique genes. Only patients who developed autoimmune disorders following treatment, signifying a robust immune response, were included. Despite evidence of an enhanced immune response, most patients eventually exhibited disease progression. Overall, data from five pre-IPI tumors and four post-IPI tumor samples (from three patients) permitted identification of several candidate genes that showed increased expression based on normalized counts after therapy. These included TTK (~3.1-fold, P=1.18e-4), which encodes a dual-specificity protein tyrosine kinase, a known cell cycle regulator, and BIRC5 (~3.0-fold, P=9.36e-4), which encodes the antiapoptotic protein survivin. Both TTK (MPS1) and survivin are targetable proteins against which a number of pharmacologic agents have been developed. CDK1, which encodes a protein tyrosine kinase known to phosphorylate survivin, was also upregulated (~3.2-fold, P=2.80-3). Tumor cell expression of TTK and survivin proteins was confirmed using immunohistochemistry in an expanded patient cohort. Differences in gene expression for several commonly encountered immune antigens, such as CD3, CD4, CD8, and CTLA4, were not statistically significant, likely reflecting the long length of time (average 323 days) between the last IPI dose and post-treatment biopsies. Although our sample size is limited, these results for the first time identify targetable genes that are significantly altered by interaction between a highly activated, IPI-treated immune system and melanoma cells.
authors.affiliation: Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Scott C
authors.initials: SC
authors.lastname: Bresler
authors.affiliation: Harvard Medical School, Boston, MA, USA.|Endocrinology Division, Department of Medicine, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Le
authors.initials: L
authors.lastname: Min
authors.affiliation: Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Rodig
authors.affiliation: Harvard Medical School, Boston, MA, USA.|Department of Dermatology, Brigham and Women's Hospital, Boston, MA, USA.
authors.forename: Andrew C
authors.initials: AC
authors.lastname: Walls
authors.affiliation: Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Shuyun
authors.initials: S
authors.lastname: Xu
authors.affiliation: Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Songmei
authors.initials: S
authors.lastname: Geng
authors.affiliation: Harvard Medical School, Boston, MA, USA.|Dana Farber Cancer Institute, Boston, MA, USA.
authors.forename: F Stephen
authors.initials: FS
authors.lastname: Hodi
authors.affiliation: Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: George F
authors.initials: GF
authors.lastname: Murphy
authors.affiliation: Program in Dermatopathology, Department of Pathology, Brigham and Women's Hospital, Boston, MA, USA.|Harvard Medical School, Boston, MA, USA.
authors.forename: Christine G
authors.initials: CG
authors.lastname: Lian
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000911:Antibodies, Monoclonal / Q000627:therapeutic use*; D015551:Autoimmunity / Q000187:drug effects* / Q000235:genetics; D060908:CTLA-4 Antigen / Q000037:antagonists & inhibitors* / Q000235:genetics / Q000276:immunology; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D016000:Cluster Analysis; D005260:Female; D020869:Gene Expression Profiling / Q000379:methods*; D015972:Gene Expression Regulation, Neoplastic / Q000187:drug effects; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007150:Immunohistochemistry; D051034:Inhibitor of Apoptosis Proteins / Q000235:genetics / Q000378:metabolism; D000074324:Ipilimumab; D008297:Male; D008545:Melanoma / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D008875:Middle Aged; D009362:Neoplasm Metastasis; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism; D012878:Skin Neoplasms / Q000188:drug therapy* / Q000235:genetics / Q000473:pathology; D000077022:Survivin
chemical_list: D000911:Antibodies, Monoclonal; C107489:BIRC5 protein, human; D060908:CTLA-4 Antigen; C556706:CTLA4 protein, human; D018797:Cell Cycle Proteins; D051034:Inhibitor of Apoptosis Proteins; D000074324:Ipilimumab; D000077022:Survivin; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; C075840:TTK protein, human