鳞状细胞癌抗原(SCCA)是卵清蛋白家族丝氨酸蛋白酶抑制剂的成员。该蛋白由Kato和Torigoe(1977)从转移性宫颈鳞状细胞癌中分离出来。SCCA在正常鳞状上皮的浅层和中间层检测到，而mRNA在基底层和基下层检测到。SCCA的临床意义是作为一种循环性鳞状细胞癌的肿瘤标志物，尤其是宫颈、头颈部、肺部和食道鳞状细胞癌。许多宫颈鳞状细胞癌的临床研究表明，SCCA循环水平升高的患者比例从0期的约12%增加到IV期的90%以上。肿瘤切除术后SCCA水平下降，在复发性疾病的患者中约90%升高。类似的趋势也发生在其他类型的鳞状细胞癌中，对肺部肿瘤的最大敏感性约为60%，对食道肿瘤的最大敏感性为50%，对头颈部肿瘤的最大敏感性为55%。中性形式的SCCA (SCCA1，或SERPINB3)在正常和一些恶性鳞状细胞的细胞质中被检测到，而酸性形式的SCCA2(或SERPINB4)主要在恶性细胞中表达，是癌症患者血浆中发现的主要形式。因此，SCCA酸性部分的出现与更具侵袭性的肿瘤相关(Schneider et al.， 1995)。Ray et al.(2005)指出，小鼠Serpinb3a，或Scca2，具有人SCCA1的半胱氨酸样丝氨酸蛋白酶抑制功能和人Scca2的胰蛋白酶样丝氨酸蛋白酶抑制功能。因此，Scca2是人类SCCA1和Scca2的小鼠同源物。Ray等人(2005)发现，用鸡卵清蛋白(OVA)挑战子宫红蛋白(UGB，或SCGB1A1)敲除小鼠会导致Scca2的肺部表达升高，以及肺细胞因子Il4和Il13的水平升高，并加剧气道炎症。这些影响被重新引入重组Ugb抵消。用IL4或IL13处理培养的人支气管上皮细胞，通过转录因子STAT1和STAT6的磷酸化刺激SCCA1和SCCA2的表达。在酪氨酸磷酸化抑制剂的存在下，SCCA1和SCCA2的表达没有被IL4或IL13上调。Ray et al.(2005)提出UGB通过下调IL4和IL13的信号，抑制SCCA1和SCCA2的表达来控制过敏性哮喘。抗Serpinb3a抗体是由纯化的大肠杆菌源重组小鼠Serpinb3a免疫获得的兔多克隆抗体。该抗体可用于Serpinb3a的免疫印迹和免疫染色检测。
Cosmo Bio抗体,Anti Squamous Cell Carcinoma Antigen 2 (SERPINB3A/SQN-5) pAb (Rabbit, Antiserum),CAC-SU-IZ-P03
Application: IHC, WB, IF
Clonality: Polyclonal
Host: Rabbit
Purification: Serum
Reactivity: Mouse
Squamous cell carcinoma antigen (SCCA) is a member of the ovalbumin family of serine proteinase inhibitors. The protein was isolated from a metastatic cervical squamous cell carcinoma by Kato and Torigoe (1977). SCCA is detected in the superficial and intermediate layers of normal squamous epithelium, whereas the mRNA is detected in the basal and sub-basal levels. The clinical import of SCCA has been as a circulating tumor marker for squamous cell carcinoma, especially those of the cervix, head and neck, lung, and esophagus. Many clinical studies of cervical squamous cell carcinoma show that the percentage of patients with elevated circulating levels of SCCA increases from approximately 12% at stage 0 to more than 90% at stage IV. Levels fall after tumor resection and rise in approximately 90% of the patients with recurrent disease. Similar trends occur in the other types of squamous cell carcinoma, with a maximum sensitivity of approximately 60% for lung, 50% for esophageal, and 55% for head and neck tumors. The neutral form of SCCA (SCCA1, or SERPINB3) is detected in the cytoplasm of normal and some malignant squamous cells, whereas the acidic form (SCCA2, or SERPINB4) is expressed primarily in malignant cells and is the major form found in the plasma of cancer patients. Thus, the appearance of the acidic fraction of SCCA is correlated with more aggressive tumors (summary by Schneider et al., 1995). Ray et al. (2005) stated that mouse Serpinb3a, or Scca2, exhibits the cysteine-like serine protease inhibitory function of human SCCA1 and the trypsin-like serine protease inhibitory function of human SCCA2. Thus, Scca2 is the mouse ortholog of both human SCCA1 and SCCA2. Ray et al. (2005) found that challenge of uteroglobin (UGB, or SCGB1A1)-knockout mice with chicken ovalbumin (OVA) resulted in elevated lung expression of Scca2, as well as elevated levels of the cytokines Il4 and Il13 in lung and exacerbated airway inflammation. These effects were countered by reintroduction of recombinant Ugb. Treatment of cultured human bronchial epithelial cells with IL4 or IL13 stimulated SCCA1 and SCCA2 expression via phosphorylation of the transcription factors STAT1 and STAT6. SCCA1 and SCCA2 expression was not upregulated by IL4 or IL13 in the presence of an inhibitor of tyrosine phosphorylation. Ray et al. (2005) proposed that UGB controls allergic asthma by downregulating signaling through IL4 and IL13 and inhibiting SCCA1 and SCCA2 expression. Anti-Serpinb3a antibody is a rabbit polyclonal antibody obtained from immunization with purified E. coli-derived recombinant mouse Serpinb3a. This antibody can be used for the detection of Serpinb3a by immunoblotting and immunostaining.