{
  "abstract": "Background Pancreatic ductal adenocarcinoma (PDAC) is characterised by a dismal prognosis and insensitivity to immune checkpoint blockers (ICBs); however, the underlying mechanism remains elusive.Objective This study aimed to identify tumour cell-intrinsic regulators that promote immune evasion and ICB resistance in PDAC.Design Multi-omics analysis and clinical cohort studies identified protein disulfide isomerase family A member 6 (PDIA6) as a regulator of the immune microenvironment. Flow cytometry, multiplex immunohistochemistry, electron microscopy and Glutathione S-Transferase (GST) pulldown assays confirmed that PDIA6 repressed PRKR-like endoplasmic reticulum kinase (PERK) activation and immunogenic cell death (ICD). Chromatin immunoprecipitation confirmed that KRAS G12D and YY1 modulated PDIA6 transcription. LSL-Kras G12D/+ ;LSL-Trp53 R172H/+ ;Pdx-1-Cre (KPC) mouse models showed that PDIA6 inhibition improved ICB response.Results Multi-omics screening identified PDIA6 as a biomarker of CD8 + T-cell paucity and poor prognosis in patients with PDAC. High PDIA6 levels predicted poor ICB response in the PDAC cohorts. PDIA6 inhibition reprogrammed the immunosuppressive tumour microenvironment and hindered mouse PDAC growth in the presence of CD8+ T-cell, which is attributed to enhanced ICD. PDIA6 interacted with cysteine 453 of PERK, abrogating the disulphide bond-mediated dimerisation and activation of PERK, an ICD inducer. Oncogenic KRASG12D potently upregulated PDIA6 via YY1-mediated transcriptional activation. We identified a small-molecule inhibitor of PDIA6, PACMA31, and demonstrated that targeting PDIA6 with PACMA31 improved ICB efficacy in a PDAC mouse model with KRAS mutations.Conclusions PDIA6, driven by KRAS G12D, alleviates ICD and promotes immune evasion, functioning as a predictive biomarker to screen ICB-sensitive patients and a therapeutic target to improve ICB efficacy in PDAC with KRAS mutations.",
  "authors": [
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Ronglin Wang"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China",
        "Biotechnology Center, School of Pharmacy, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Junqiang Li"
    },
    {
      "affiliations": [
        "Department of Obstetrics and Gynecology, Tangdu Hospital, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Danjie Su"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Jing Yang"
    },
    {
      "affiliations": [
        "Department of Oncology, Second Medical Center, Chinese People’s Liberation Army (PLA) General Hospital, Beijing, China"
      ],
      "name": "Peixiang Ma"
    },
    {
      "affiliations": [
        "Department of Emergency, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China"
      ],
      "name": "Lei Hua"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Jing Luo"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Jingyi Liu"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Rui Yang"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Liang Zhang"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Xiangjing Shen"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Hongrui Wang"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Hong Li"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Ting Zhao"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Jie Min"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Lili Liu"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Chenggong Liao"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Yang Song"
    },
    {
      "affiliations": [
        "Department of Oncology Tangdu Hospital, the State Key Laboratory of Holistic Integrative Management of Gastrointestinal Cancers, Fourth Military Medical University, Xi’an, Shaanxi, China"
      ],
      "name": "Haichuan Su"
    }
  ],
  "title": "KRAS-driven protein disulfide isomerase family A member 6 expression suppresses PRKR-like endoplasmic reticulum kinase-mediated immunogenic cell death to desensitise pancreatic ductal adenocarcinoma to immune checkpoint blockers",
  "uid": "e7ab387d-fcb2-5553-8f63-139ea6998952"
}