Ring finger protein 157 is a prognostic biomarker and is associated with immune infiltrates in human breast cancer

Background: The protein encoded by ring finger protein 157 (RNF157) is known to function as an E3 ubiquitinligase. However, whether the level of RNF157 expression in breast cancer correlates with prognosis and immune cellinfiltration among breast cancer patients remains to be further explored. Methods: In this study, publicly availabledatasets were used for evaluating RNF157 expression in different tumors compared with normal samples. Severalindependent datasets were screened for investigating the relationship between RNF157 and breast cancer survival,different mutation profiles, and tumor immune cell infiltration. We conducted a pathway enrichment analysis toidentify signaling pathways associated with RNF157. Results: Analysis of public and online databases revealed thatRNF157 expression markedly decreased in breast cancer tissue samples compared to non-carcinoma counterparts.Consistently, immunohistochemistry assays also demonstrated this RNF157 down-regulation in breast cancer samples.RNF157 up-regulation could predict the improved survival of breast cancer cases. Further, different RNF157expression level groups exhibited different mutational profiles. Pathway enrichment profiling of RNF157-related genessuggested its possible involvement in regulating breast cancer via the mitogen-activated protein kinase (MAPK)pathway. RNA sequencing (RNA-seq) data and genomic enrichment analysis showed that RNF157 downregulatedseveral genes positively associated with the MAPK signaling pathway. We also explored RNF157 expression andimmune cell infiltration in breast cancer and found that RNF157 mRNA levels were negatively related to non-Timmune cell infiltration. Conclusion: According to our work, RNF157 may be a promising diagnostic biomarker andtherapeutic target for breast cancer.

环指蛋白157通过下调小凹蛋白-1表达参与ERK通路激活促进黑素瘤细胞增殖

目的探讨环指蛋白157(RING finger protein 157,RNF157)在黑素瘤细胞增殖中的作用及相关机制。方法采用慢病毒转染技术构建RNF157过表达黑素瘤细胞株,小干扰RNA(siRNA)技术构建敲减RNF157的黑素瘤细胞株,采用实时荧光定量聚合酶链反应(qRT-PCR)和Western印迹实验验证转染效果。采用MTT实验、克隆形成实验检测RNF157过表达黑素瘤细胞和敲减RNF157黑素瘤细胞的细胞增殖能力。采用裸鼠皮下成瘤实验及免疫组化染色检测RNF157过表达黑素瘤细胞体外增殖能力。采用免疫共沉淀(Co-IP)结合质谱分析、蛋白质组学和泛素化组学,探究RNF157在ERK通路中的潜在作用机制。结果免疫组化染色结果显示,RNF157在黑素瘤组织中的表达高于瘤旁组织(P<0.01)。qRT-PCR和Western印迹实验结果显示,过表达组的RNF157表达水平显著高于对照组(P<0.0001);si3转染效率最高,si3组的RNF157表达水平显著低于对照组(P<0.01)。MTT实验、克隆形成实验结果显示,RNF157过表达可促进黑素瘤细胞增殖,敲减RNF157抑制黑素瘤细胞增殖。进一步检测发现,RNF157过表达可以激活黑素瘤细胞的ERK通路。Co-IP结合质谱分析、蛋白质组学和泛素化组学结果显示,RNF157可结合小凹蛋白-1(caveolin-1,CAV1)并下调其表达水平,从而调控ERK通路。结论RNF157可促进黑素瘤细胞的体内外增殖;在黑素瘤细胞中,RNF157可能通过结合并下调CAV1表达水平,参与细胞内ERK通路激活。