Among the diagnostic techniques for the identification of tumour biomarkers, the liquid biopsy is considered one that offers future research on precision diagnosis and treatment of tumours in a non-invasive manner. The approach consists of isolating tumor-derived components, such as circulating tumour cells (CTC), tumour cell-free DNA (ctDNA), and extracellular vesicles (EVs), from the patient peripheral blood fluids. These elements constitute a source of genomic and proteomic information for cancer treatment. Within the tumour-derived components of the body fluids, the enzyme indicated with the acronym CA IX and belonging to the superfamily of carbonic anhydrases (CA, EC 4.2.1.1) is a promising aspirant for checking tumours. CA IX is a transmembrane-CA isoform that is strongly overexpressed in many cancers being not much diffused in healthy tissues except the gastrointestinal tract. Here, it is summarised the role of CA IX as tumour-associated protein and its putative relationship in liquid biopsyfor diagnosing and monitoring cancer progression.

中文翻译：

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碳酸酐酶IX作为液体活检中的新型候选药物。

在用于鉴定肿瘤生物标志物的诊断技术中，液体活检被认为是一种以无创方式对肿瘤的精确诊断和治疗进行进一步研究的技术。该方法包括从患者外周血液中分离出肿瘤来源的成分，例如循环肿瘤细胞（CTC），无肿瘤细胞的DNA（ctDNA）和细胞外囊泡（EV）。这些成分构成了用于癌症治疗的基因组和蛋白质组学信息的来源。在体液的肿瘤衍生成分中，首字母缩写为CA IX的酶属于碳酸酐酶的超家族（CA，EC 4.2.1.1），是检查肿瘤的有希望的吸引剂。CA IX是跨膜CA的同工型，在许多癌症中强烈过量表达，除了胃肠道外，在健康组织中的扩散不多。在此，概述了CA IX作为肿瘤相关蛋白的作用及其在液体活检中诊断和监测癌症进展的假定关系。