Alterations in DNA Damage following Major Surgery and Hyperthermic Intraperitoneal Chemotherapy

摘要/摘要 近10%的转移性结直肠癌(MCRC)患者的疾病进展涉及 转移性癌症向腹膜腔扩散。这些患者的结果通常是最差的。 多发性结直肠癌患者。最近的一项III期多中心临床试验表明，单剂免疫检查点 与标准的细胞毒化疗方案相比，抑制剂(ICI)具有更好的疗效和安全性 多发性结直肠癌患者。重要的是，接受ICI治疗的适应症取决于HIGH的测量。 肿瘤突变负荷(TMB)、新抗原负荷和微卫星不稳定性(MSI)状态。这些直接和 基因组不稳定性的间接测量可以预测ICIS的临床反应，然而，只有5%的患者是 目前有资格接受这些治疗。 有腹膜扩散的多发性结直肠癌患者可接受大型细胞减少性手术。 所有肉眼的病变部位都被切除了。CRS联合热化疗术 在43°C下使用丝裂霉素C(Hipec)可根除微小疾病。我们假设大手术 CRS的炎症和HIPEC的高温和化疗共同增加了基因组的不稳定性。 众所周知，外科炎症会激活热休克蛋白(HSPs)，这可能会破坏其调控的稳定性 过度错配修复(MMR)蛋白导致DNA修复缺陷。这种情况与DNA结合在一起 丝裂霉素c和热的损伤作用可能导致高TMB、新抗原增加和MSI改变。 神秘显微镜下的mCRC细胞。我们的主要假设是接受CRS/HIPEC的患者将是 有资格接受ICI治疗并将从中受益。 我们建议在CRS/HIPEC前后采集mCRC患者的血样和手术组织。 将对这些标本进行TMB和新抗原(AIM 1)和MMR/MSI(AIM 2)的变化评估。从… 手术组织，我们还将创建成对的患者衍生器官(PDO)，我们将从中进行研究 热休克蛋白、MMR蛋白和MSI。我们先前使用CRS/HIPEC患者的PDO进行的研究支持他们使用PDO 评估CRS/HIPEC前后ICI治疗的敏感性。我们提出了以下具体目标： 具体目标1.测量高温和DNA损伤引起的TMB和新抗原的变化 丝裂霉素C在接受CRS/HIPEC治疗的mCRC患者中的作用 具体目的2.确定外科炎症与高温和DNA损伤是否联合作用 来自CRS/HIPEC的丝裂霉素C破坏MMR蛋白的HSP稳定，从而增加MSI。

ABSTRACT/SUMMARY Nearly 10% of patients with metastatic colorectal cancer (mCRC) have progression of disease involving the spread of metastatic cancer to the peritoneal cavity. These patients generally have the worst outcomes for all patients with mCRC. A recent phase III multicenter clinical trial has shown that single-agent immune checkpoint inhibitor (ICI) has greater efficacy and better safety profile than standard cytotoxic chemotherapy regimens for patients with mCRC. Importantly, indications to receive ICI therapy are dependent on the measurement of high tumor mutation burden (TMB), neoantigen burden, and microsatellite instability (MSI) status. These direct and indirect measures of genomic instability predict clinical response to ICIs, however, only 5% of patients are currently eligible to receive these therapies. Patients with mCRC with peritoneal spread of disease may undergo major cytoreductive surgery (CRS), during which all gross sites of disease are resected. CRS is combined with heated intraperitoneal chemotherapy (HIPEC) with mitomycin C at 43°C to eradicate microscopic disease. We hypothesize that major surgical inflammation from CRS and the heat and chemotherapy of HIPEC altogether increase genomic instability. Surgical inflammation is known to activate heat shock proteins (Hsps) which may destabilize its regulatory control over mismatch repair (MMR) proteins leading to deficient DNA repair. This condition combined with the DNA damaging effects of mitomycin c and heat may lead to high TMB, increased neoantigens, and altered MSI in occult microscopic mCRC cells. Our overarching hypothesis is that patients undergoing CRS/HIPEC will be eligible to receive and will benefit from ICI therapy. We propose to obtain blood samples and surgical tissues before and after CRS/HIPEC from patients with mCRC. These specimens will be assessed for changes in TMB and neoantigens (Aim 1) and MMR/MSI (Aim 2). From the surgical tissues, we will also create paired patient-derived organoids (PDOs) from which we will investigate Hsps, MMR proteins, and MSI. Our prior studies using PDOs from CRS/HIPEC patients support their use to assess sensitivities to ICI therapies before and after CRS/HIPEC. We propose the following specific aims: Specific Aim 1. To measure alterations in TMB and neoantigens as a result of the heat and DNA damaging effects of mitomycin C in mCRC patients undergoing CRS/HIPEC. Specific Aim 2. To determine whether surgical inflammation combined with heat and DNA damaging effects of mitomycin C from CRS/HIPEC disrupt Hsp-stabilization of MMR proteins to increase MSI.