TUMOR MARKERS o Tumor index substances released from the tumor - - PowerPoint PPT Presentation

TUMOR MARKERS

• Tumor index substances – released from the tumor cells,

which could be detected in blood and indicate the presence

• f tumor in the body
• Used for the follow-up of cancer and to monitor the

effectiveness of the therapy

• Diagnosis of cancer
• Prognostic use
• Localization

CLINICALLY IMPORTANT TUMOR MARKERS:

• 1. AFP (alpha fetoprotein):

Molecular weight = 70,000 Daltons It is a fetal albumin Increased values are seen in the circulation of patients with hepatocellular carcinoma, germ cell tumors, teratocarcinoma of ovary and in pregnancy with fetal malformations of neural tube

• 2. CARCINOEMBRYONIC ANTIGEN (CEA):

Its level is markedly increased in colorectal cancers

• 3. PROSTATIC SPECIFIC ANTIGEN (PSA):

Produced by secretary epithelium of prostatic gland It is normally secreted in to seminal fluid, where it is necessary for the liquifaction of seminal coagulum Increased PSA level is seen in prostate cancer

• 4. BETA CHAIN OF CHORIONIC

GONADOTROPHIN: It is synthesised by normal syncytiotrophoblasts (cells

• f placental villi)

The hCG has alpha and beta subunits Increased levels are seen in choriocarcinoma and germ cell tumors

NAME SERUM LEVELS INCREASED IN Oncofetal Products: Alpha fetoprotein (AFP) Carcinoembryogenic antigen (CEA) Hepatoma, germ cell cancers Colorectal, gastrointestinal & lung cancer Carbohydrate Antigens: CA - 125 Ovarian cancer of epithelial origin Tissue Antigens: Tissue polypeptide antigen General cancer Tissue catabolic product: Hydroxy proline Bone metastasis Serum Proteins: Immunoglobulins (Ig) Bence-Jones Proeins (in urine) Multiple myeloma, macroglobulinemia Multiple myeloma

TUMOR MARKERS

NAME SERUM LEVELS INCREASED IN Enzymes:

1.

Alkaline phosphatase (ALP)

2.

Placental ALP (Regan)

3.

Prostatic acid phosphatase (PAP)

4.

Prostate specific antigen (PSA)

5.

Neuron specific enolase Bone cancers Lung, seminoma Prostate cancer Prostate cancer Tumors of nervous system Hormones:

1.

Beta – hCG

2.

Calcitonin Choriocarcinoma Medullary thyroid carcinoma

ONCOGENES: Genes capable of causing cancer The oncogenes present in normal cells are also called as proto-oncogenes Proto-oncogenes are located on specific chromosomes Products of many oncogenes are polypeptide growth factors, e.g., sis gene produces platelet derived growth factor (PDGF) Some products act as receptor for epithelial growth factor

• 1. Erb – B:
• Located in chromosome no 7
• The gene is carried by erythroblastosis virus in chicken
• Its product is receptor for epidermal growth factor

(EGFR)

• Subcellular localization: Membrane
• 2. Erb – A:
• Located in chromosome no 17
• The gene is carried by erythroblastosis virus in chicken
• Transforming growth factor receptor (TGF-R)
• Subcellular localization: Nucleus

src:

Located in the chromosome no 20 carried by rous sarcoma in chicken Oncogene product: Tyrosine kinase Subcellular localization: Membrane

sis:

Located in chromosome no 22 Carried by simian sarcoma virus in monkey Oncogene product: Platelet derived growth factor (PDGF) Subcellular localization: Membrane

ras:

Located in the chromosome no 12 Carried by rat sarcoma Oncogene product: GTPase Subcellular Localization: Cytoplasm