Subcellular expression of maspin – from normal tissue to tumor cells

Table 1 Maspin expression in placenta, mammary gland, and urogenital organs

Organ/ tissue	Subcellular expression in normal tissue	Subcellular expression in pathologic conditions
Placenta	Cytoplasm: Syncytio- and cytotrophoblasts, and endothelial cells; Nucleus: Chorionic plate	Preeclampsia: Upregulation
Mammary gland	Cytoplasm: Myoepithelial cells (intense in pregnancy and lactation); Nucleus: Myoepithelial cells	Invasive breast cancer: Maspin positivity is more frequent in ductal than lobular carcinomas; Cytoplasm only: Negative prognostic indicator, ER and PgR negativity; Nucleus: Better prognosis, ER and PgR positivity; Negativity: Loss or cytoplasm to nuclear translocation in metastatic tissue
Ovary	Negative	Benign tumors: Negative or infrequent nuclear; Ovarian carcinomas: Cytoplasm only: Cisplatin sensitivity; Mixed expression (cytoplasm and nucleus): Indicator of low malignant potential
Uterine cervix	Squamous epithelium: Cytoplasmic and nuclear staining	CIN3: Cytoplasm: Down regulation; Nucleus: Upregulation; Squamous cell carcinoma: Cytoplasm: Tumor suppressor role; Adenocarcinoma: Cytoplasm: Aggressive behavior
Uterine body	Negative or positive (mostly nuclear) staining in normal endometrial glands; Low intensity in atrophic endometrium	Endometrial hyperplasia: Nucleus: Indicator of atypia; Endometrioid endometrial adenocarcinoma: Cytoplasm: Aggressive behavior; Nucleus: Better prognosis
Prostate	Basal cells: Positive; Secretory cells: Negative	HGPIN: Basal cells: Positive (same intensity as normal); Secretory cells: Positive; Adenocarcinoma: Low-grade carcinoma: Reduced expression compared with HGPIN; High-grade carcinoma: Low or no expression
Urinary bladder	Positive in epithelial cells	Urothelial carcinoma: Nucleus: Better prognosis

CIN: Cervical intraepithelial neoplasia; ER: Estrogen receptor; HGPIN: High-grade prostate intraepithelial neoplasia; PgR: Progesterone receptor.

Table 2 Maspin expression in organs of the respiratory and gastroenteropancreatic system

Organ/ tissue	Subcellular expression in normal tissue	Subcellular expression in pathologic conditions
Lung	Bronchial basal cells: Nuclear staining; Alveolocytes: Negative	Non-small cell carcinomas: Cytoplasm only: Negative prognostic factor; Nucleus only: Low aggressivity
Esophagus	Squamous epithelium: Negative or weak cytoplasm	SCC: Nucleus: Low pTNM stage; Cytoplasm: Risk for lymph node metastases
Stomach	Foveolar and glandular cells: Cytoplasm or negative	Dysplasia: Nucleus: High-grade dysplasia; Carcinomas: Cytoplasm: Better prognosis; Nuclear: Local aggressive behavior; Negative: Risk for distant metastases or neuroendocrine component
Colon and rectum	Normal mucosa: Cytoplasm or negative	Dysplasia: Nucleus: High-grade dysplasia; Adenocarcinoma: Cytoplasm only: Low-grade tumor, low risk for metastases, high chance for MSI-H status; Nuclear only: High pTNM stage, high-grade budding; Negative: Risk for distant metastases or neuroendocrine component
Liver and intrahepatic biliary ducts	Negative in most of the normal hepatocytes and in normal biliary ducts	Carcinoma: Positive (cytoplasmic, nuclear or mixed cyto-nuclear expression), with unknown significance
Pancreas	Negative in exo- and endocrine pancreas	PanIN grade 1 and grade 2: Negative; PanIN grade 3 and PDAC: Positive (cytoplasmic and nuclear staining); Endocrine tumors: Negative; Ductal adenocarcinoma: Nuclear
Gallbladder	Negative or positive (cyto-nuclear staining)	Dysplasia: Negative or weak staining; BilIN, carcinoma: Cyto-nuclear expression gradually increases from normal epithelium to BilIN and carcinoma

BilIN: Biliary intraepithelial neoplasia; MSI-H: High microsatellite instability; PanIN: Pancreatic intraepithelial neoplasia; SCC: Squamous cell carcinoma; PDAC: Pancreatic ductal adenocarcinoma

Table 3 Maspin expression in brain, organs of the head and neck area, skin and soft tissues

Organ/ tissue	Subcellular expression in normal tissue	Subcellular expression in pathologic conditions
Brain	Positive in nucleus and cytoplasm	Decreased expression in parallel with the advancing glioma stage
Head and neck	Cytoplasm: Oral cavity epithelium and temporal bone; Nucleus: Salivary glands: Myoepithelial cells, basal cells of the ducts and some luminal cells; Negative: Salivary glands: Secretory cells	Oral SCC: Cytoplasm (better prognosis); Temporal bone SCC: Negative, cytoplasm-only or cyto-nuclear; Salivary glands: Pleomorphic adenoma (cyto-nuclear or cytoplasmic only), Warthin’s tumor (cyto-nuclear or cytoplasmic only, weaker than in pleomorphic adenoma), adenoid cystic carcinoma, mucoepidermoid carcinoma (cytoplasmic only, negative in an anaplastic variant of adenoid cystic carcinoma); Laryngeal SCC: Cytoplasm and nucleus
Thyroid	Negative	Negative follicular adenoma, follicular carcinomas, poorly and undifferentiated carcinomas; Cytoplasm: Papillary thyroid carcinoma
Skin	Cytoplasmic: Normal epidermis; Nuclear: Myoepithelial cells of the sweat glands and mature sebaceous glands	SCC: Cytoplasm expression in low stages and nuclear staining in dedifferentiated tumors; Basal cell carcinoma: Cytoplasm and nucleus; Melanoma: Nuclear expression is an indicator of aggressiveness
Soft tissue	Negative	Inflammation: Negative; Lipoma, atypical lipomatous tumor: Cytoplasm; Sarcomas: Cytoplasm or nucleus, as indicators of aggressive behavior

SCC: Squamous cell carcinoma.