The expression of major histocompatibility complex class I (MHC I) in tumor cells is regulated by interferon signaling, and it is an important factor in the efficacy of cytotoxic T cell-dependent immunotherapy. To determine the impact of immune cells in MHC I expression on tumor cells, we compared the expression of MHC I in tumor cells derived from primary breast cancers and patient-derived xenograft (PDX) models. MHC I and myxovirus resistance gene A (MxA) expression were analyzed using immunohistochemistry in 23 cases of tumor tissue and corresponding primary and secondary PDXs. The median H score of MHC I was 210 (0-300) in patient tumor tissues, 197.5 (0-300) in primary PDX tumors, and 157.5 (5-300) in secondary PDX tumors. Cases were divided into four groups based on the difference in MHC I expression between the patient tumor tissues and secondary PDXs. Eleven cases constituted the high MHC I group, four constituted the low MHC I group, six comprised the decreased MHC I group, and two comprised the increased MHC I group. MHC I and MxA expressions in each tumor were weakly correlated within patients' tumors, while strongly correlated within PDX models. Retained or altered expression of MHC I in breast cancer PDXs reveals the presence of intrinsic and extrinsic interferon signaling pathways in tumor cells. Thus, considering MHC I expression in PDX is important when using PDX models to evaluate the efficacy of cancer immunotherapy in a preclinical setting.

中文翻译：

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乳腺癌患者异种移植模型中主要组织相容性复合体I类的表达保持或改变。

肿瘤细胞中主要组织相容性复合物I类（MHC I）的表达受干扰素信号传导的调节，它是细胞毒性T细胞依赖性免疫疗法疗效的重要因素。为了确定免疫细胞中MHC I表达对肿瘤细胞的影响，我们比较了MHC I在原发性乳腺癌和患者衍生异种移植（PDX）模型衍生的肿瘤细胞中的表达。使用免疫组织化学分析了23例肿瘤组织以及相应的原发性和继发性PDX中的MHC I和黏液病毒抗性基因A（MxA）的表达。患者肿瘤组织中MHC I的中位H评分在原发性PDX肿瘤中为210（0-300），在原发性PDX肿瘤中为197.5（0-300），在继发性PDX肿瘤中为157.5（5-300）。根据患者肿瘤组织和继发性PDXs之间MHC I表达的差异，将病例分为四组。高MHC I组11例，低MHC I组4例，降低的MHC I组6例，增加的MHC I组2例。每个肿瘤中MHC I和MxA的表达在患者肿瘤中呈弱相关，而在PDX模型中则呈强相关。MHC I在乳腺癌PDX中的表达保持或改变揭示了肿瘤细胞中内源性和外源性干扰素信号通路的存在。因此，在使用PDX模型评估临床前环境中癌症免疫疗法的疗效时，考虑PDX中MHC I的表达很重要。6个是MHC I组降低，而2个是MHC I组升高。每个肿瘤中MHC I和MxA的表达在患者肿瘤中呈弱相关，而在PDX模型中则呈强相关。MHC I在乳腺癌PDX中的表达保持或改变揭示了肿瘤细胞中内源性和外源性干扰素信号通路的存在。因此，在使用PDX模型评估临床前环境中癌症免疫疗法的疗效时，考虑PDX中MHC I的表达很重要。6个是MHC I组降低，而2个是MHC I组升高。每个肿瘤中MHC I和MxA的表达在患者肿瘤中呈弱相关，而在PDX模型中则呈强相关。MHC I在乳腺癌PDX中的表达保持或改变揭示了肿瘤细胞中内源性和外源性干扰素信号通路的存在。因此，在使用PDX模型评估临床前环境中癌症免疫疗法的疗效时，考虑PDX中MHC I的表达很重要。MHC I在乳腺癌PDX中的表达保持或改变揭示了肿瘤细胞中内源性和外源性干扰素信号通路的存在。因此，在使用PDX模型评估临床前环境中癌症免疫疗法的疗效时，考虑PDX中MHC I的表达很重要。MHC I在乳腺癌PDX中的表达保持或改变揭示了肿瘤细胞中内源性和外源性干扰素信号通路的存在。因此，在使用PDX模型评估临床前环境中癌症免疫疗法的疗效时，考虑PDX中MHC I的表达很重要。