CA125 Protein, Human (HEK293, His)

CA125 is a giant mucin-like glycoprotein expressed by epithelial ovarian neoplasms and cells, which is an antigenic tumor marker. CA125 provides a protective, lubricating barrier against particles and infectious agents at mucosal surfaces. CA125 binds to mesothelin (MSLN) mediates heterotypic cell adhesion, contributing to the metastasis of ovarian cancer to the peritoneum by initiating cell attachment to the mesothelial epithelium. CA125 is widely used for monitoring with ovarian epithelial cancer. CA125 Protein, Human (HEK293, His) is a recombinant human cancer antigen 125 (CA125) with a His label and is expressed in HEK293 cells^{[1][2][3][4][5][6][7]}.

CA125 Protein (Human) is a counter receptor for galectin-1, as both soluble and membrane-associated fragments of CA125 derived from HeLa cell lysates are shown to bind specifically to human galectin-1 with high efficiency^[1].
CA125 Protein (Human) is one of the mucin family proteins and is a serum tumor marker for various tumors, such as ovarian cancer, endometrial cancer, pancreatic cancer and bladder cancer^[2].
CA-125 Protein (Human) is correlated with both peritoneal carcinomatosis on the diaphragm and residual disease (RD): A CA-125 (Human) value above 500 U/ml induction on the risk of diaphragmatic carcinomatosis is 3.5 times higher and the risk for residual disease of any size is increased by 2.4 times^[3].
CA125 Protein (Human) is an antigen epitope found on mucin 16 (MUC16), a glycoprotein antigen present on the cell surface. Currently, 3 antibodies can help identify the CA125 antigen: OC125-like antibodies, M11-like antibodies and OV197-like antibodies. Postmenopausal women with a CA125 Protein (Human) level higher than 35 U/mL are considered to have a high risk of a malignancy^[4].
CA125 Protein (Human) affects the cellular function of cancer cells, including fending off cytotoxic natural killer cell attacks and modulating intracellular signaling pathways in cancer cells or noncancer cells in the tumor-microenvironment (TM)^[5].

The N-, O-linked sugar moieties and and the proteinaceous core structure of CA125 Protein (Human) contribute to the specificity of galectin recruitment. Additionally, CA125-C-TERM binding to galectin-1 largely depends on O-linked β-galactose-terminated oligosaccharide chains^[1].
The expression levels of M2 macrophage marker, CD163 and regulatory T-cell (Treg) marker, FOXP3 are higher in CD125 Protein (Human)-high group than in CD125 Protein (Human)-low group, suggesting CD125 Protein (Human)-high bladder cancers have the immunosuppressive tumor-microenvironment (iTM)^[5].

The affinity of CA125 protein (Human) for monoclonal antibody 196-14 is higher than that for monoclonal antibody 196-28 in nude mice bearing OVA-5 xenografts^[7].

1. Immobilized Human Mesothelin at 10 μg/mL (100 μl/well) can bind recombinant Human CA125, His (HEK293-expressed) (rHuCA125, His).The ED₅₀ of recombinant Human CA125, His (HEK293-expressed) (rHuCA125, His) is ≤2 μg/mL.
2. Immobilized Recombinant Human MSLN/Mesothelin Protein at 2 μg/mL (100 μl/well) can bind Biotinylated Recombinant Human CA125 Protein. The ED₅₀ for this effect is 5.731 ng/mL, corresponding to a specific activity is 1.74×10⁵ Unit/mg.

• 
  Immobilized Recombinant Human MSLN/Mesothelin Protein at 2 μg/mL (100 μl/well) can bind Biotinylated Recombinant Human CA125 Protein. The ED₅₀ for this effect is 5.731 ng/mL, corresponding to a specific activity is 1.74×10⁵ Unit/mg.

Human

HEK293

C-6*His

Q8WXI7 (G12660-M12923)

94025  [NCBI]

GFTHWIPVPTSSTPGTSTVDLGSGTPSSLPSPTTAGPLLVPFTLNFTITNLKYEEDMHCPGSRKFNTTERVLQSLLGPMFKNTSVGPLYSGCRLTLLRSEKDGAATGVDAICTHRLDPKSPGVDREQLYWELSQLTNGIKELGPYTLDRNSLYVNGFTHQTSAPNTSTPGTSTVDLGTSGTPSSLPSPTSAGPLLVPFTLNFTITNLQYEEDMHHPGSRKFNTTERVLQGLLGPMFKNTSVGLLYSGCRLTLLRPEKNGAATGMHHHHHH

40-80 kDa

• 
  Greater than 95% as determined by reducing SDS-PAGE.

Lyophilized powder.

Lyophilized after extensive dialysis against 50 mM Tris, 100 mM Glycine, pH 7.5 or 50 mM Tris-HCL, 300 mM NaCl, 100 mM Glycine, pH 7.4.

<1 EU/μg, determined by LAL method.

It is not recommended to reconstitute to a concentration less than 100 μg/mL in ddH₂O. For long term storage it is recommended to add a carrier protein (0.1% BSA, 5% HSA, 10% FBS or 5% Trehalose).

Stored at -20°C for 2 years. After reconstitution, it is stable at 4°C for 1 week or -20°C for longer (with carrier protein). It is recommended to freeze aliquots at -20°C or -80°C for extended storage.

Room temperature in continental US; may vary elsewhere.

• [1]. Claudia Seelenmeyer, et al. The cancer antigen CA125 represents a novel counter receptor for galectin-1. J Cell Sci. 2003 Apr 1;116(Pt 7):1305-18.  [Content Brief]

  [2]. Jacobs I,et al. The CA 125 tumour-associated antigen: a review of the literature. Hum Reprod. 1989 Jan;4(1):1-12.  [Content Brief]

  [3]. Plana A, et al. Radiologically enlarged cardiophrenic lymph nodes and CA-125 in relation to diaphragmatic carcinomatosis, surgical outcome, and overall survival in advanced ovarian cancer. Acta Oncol. 2023 May;62(5):451-457.  [Content Brief]

  [4]. Zhang R, et al. Molecular Biomarkers for the Early Detection of Ovarian Cancer. Int J Mol Sci. 2022 Oct 10;23(19):12041.  [Content Brief]

  [5]. Yamashita T, et al. Cancer Antigen 125 Expression Enhances the Gemcitabine/Cisplatin-Resistant Tumor Microenvironment in Bladder Cancer. Am J Pathol. 2023 Mar;193(3):350-361.  [Content Brief]

  [6]. Kobayashi H, et al. A human/mouse chimeric monoclonal antibody against CA125 for radioimmunoimaging of ovarian cancer. Cancer Immunol Immunother. 1993 Aug;37(3):143-9.  [Content Brief]

  [7]. Saga T, et al. An antibody-tumor model for the targeting of CA125-producing gynecologic malignancies[J]. Japanese journal of cancer research, 1990, 81(11): 1141-1148.  [Content Brief]