Biomarker: COX-2

Histology type: endometrial carcinoma

Stage: high grade

Country: Greece

Region: Athens

Followed up time :

Subgroup 1 name : negative

Subgroup 1 number: 100

Subgroup 2 name: positive

Subgroup 2 number: 26

Conclusion: Immunocytochemical findings from COX-2 stain in cancer cells could be a predictor of prognosis in most cases in endometrial cytology with imprint smears. Furthermore, positive expression of COX-2 in cancer cells was related to morphologic features of more aggressiveness tumors.

Sample type : tissue

Sample method: immunohistochemistry

Expression pattern : expression (staining intensity-color index≥1)

Expression elevation: The staining intensity (staining intensity-color index) was graded into four categories, from 0 to 3 (0, negative finding; 1, weak intensity; 2, moderate intensity; and 3, strong intensity). The percentage of cytoplasmic staining area (cytoplasmic staining area-index of positivity) was scored from 0 to 3 (index 0, no immunocytochemically positive cells; index 1:1%-10% positive cells; index 2:11%-50% positive cells; index 3: >51% positive cells). The sum of both parameters gave the immunocytochemical score (total score). Tumors were categorized into three groups depending on total score. Group I corresponded to a total score of 0, 1, or 2, group II to a total score of 3 or 4, and group III to a total score of 5 or 6. Group I tumors were considered as negative, whereas groups II and III tumors were considered as positive.

Statictics: Median;Range

Cohort age: 68.3 ; 37 -82

Funtion Uniprot: Component of the cytochrome c oxidase, the last enzyme in the mitochondrial electron transport chain which drives oxidative phosphorylation. The respiratory chain contains 3 multisubunit complexes succinate dehydrogenase (complex II, CII), ubiquinol-cytochrome c oxidoreductase (cytochrome b-c1 complex, complex III, CIII) and cytochrome c oxidase (complex IV, CIV), that cooperate to transfer electrons derived from NADH and succinate to molecular oxygen, creating an electrochemical gradient over the inner membrane that drives transmembrane transport and the ATP synthase. Cytochrome c oxidase is the component of the respiratory chain that catalyzes the reduction of oxygen to water. Electrons originating from reduced cytochrome c in the intermembrane space (IMS) are transferred via the dinuclear copper A center (CU(A)) of subunit 2 and heme A of subunit 1 to the active site in subunit 1, a binuclear center (BNC) formed by heme A3 and copper B (CU(B)). The BNC reduces molecular oxygen to 2 water molecules using 4 electrons from cytochrome c in the IMS and 4 protons from the mitochondrial matrix.

UniProt ID: P00403

UniProt Link: https://www.uniprot.org/uniprotkb/P00403/entry

Biological function from UniProt: #Electron transport #Respiratory chain #Transport

Molecular function from UniProt:

Subcellular UniProt: #Membrane #Mitochondrion #Mitochondrion inner membrane

Alternative name from UniProt:

Catalytic activity: 4 Fe(II)-[cytochrome c] + 8 H+(in) + O2 = 4 Fe(III)-[cytochrome c] + 4 H+(out) + 2 H2O，This reaction proceeds in the forward direction.

Recommended name: Cytochrome c oxidase subunit 2

Gene name from HGNC: MT-CO2 (CO2, COX2, MTCO2)

HPA class: Disease related genes Enzymes Human disease related genes Metabolic proteins Potential drug targets Transporters

AlphaFold DB: P00403

AlphaFold Link: https://alphafold.ebi.ac.uk/entry/P00403

HPA link: https://www.proteinatlas.org/ENSG00000198712-MT-CO2

Tissue specificity RNA from HPA: Tissue enhanced (brain, heart muscle)

Tissue expression from HPA: Ubiquitous cytoplasmic expression with a granular pattern.

Single cell type specificity Cell type enriched (Cardiomyocytes)

Immune cell specificity: Low immune cell specificity

Cancer prognostic summary HPA Prognostic marker in liver cancer (favorable) and pancreatic cancer (favorable)

Pathology link: https://www.proteinatlas.org/ENSG00000198712-MT-CO2/pathology

Pathology endo: https://www.proteinatlas.org/ENSG00000198712-MT-CO2/pathology/endometrial+cancer

Phenotype ID: 220110;

Disease: Mitochondrial complex IV deficiency (MT-C4D)

Note1: The disease is caused by variants affecting the gene represented in this entry

OMIM: 516040

OMIM link1: https://www.omim.org/entry/220110

OMIM link2: https://www.omim.org/entry/516040

HGNC ID: HGNC:7421

HGNC link: https://www.genenames.org/data/gene-symbol-report/#!/hgnc_id/HGNC:7421