Tumor Marker:- Part 5 – M-band, NMP 22, BTA, Oncogenes
- Tumor markers in the diagnosis and monitoring of the tumors, some more examples.
M Band of Multiple Myeloma
- The monoclonal band of immunoglobulin is used as a tumor marker.
- Myeloma components or M band or monoclonal paraprotein is used to diagnose multiple myeloma.
- Myeloma protein is an abnormal immunoglobulin fragment, such as an immunoglobulin light chain, that is produced in excess by an abnormal monoclonal proliferation of plasma cells, typically in multiple myeloma.
- Other terms used are M protein, M component, M spike, or paraprotein.
- This M protein is found in the serum and the urine electrophoresis.
- > 90 % of patient will Multiple myelomas shows M band in electrophoresis.
- The M band (protein) is paraprotein visible on electrophoresis. giving a tall peak on a densitometer, also called M spike.
- Bence-Jones protein is a light chain excreted in the urine of Multiple myeloma cases.
- Decreasing the level of Bence-Jones protein in the treatment shows a good response to treatment.
- M band in the myeloma patients on electrophoresis, when total protein is 8.8 g/dL:
Protein fractions | Result in % | The result of myeloma patient g/dL | Normal range g/dL |
Albumin | 35.2 | 3.1 | 3.5 to 5.2 |
α1 – globulin | 3.4 | 0.3 | 0.2 to 0.4 |
α2 – globulin | 6.8 | 0.6 | 0.4 to 0.8 |
β – globulin | 8.0 | 0.7 | 0.5 to 1.1 |
γ – globulin (M band) | 46.6 | 4.1 | 0.6 to 1.3 |
NMP22 (Nuclear matrix apparatus protein)
- Other names are Bladder cancer marker or bladder tumor antigen
- Nuclear matrix proteins made the internal structure of the nucleus.
- This bladder tumor antigen is a factor H-related protein that is produced by the bladder tumor.
- NMP 22 is a nuclear matrix protein that is deposited in the urine during the apoptosis of bladder cancer cells.
- Their role is the regulation of DNA replication and synthesis of RNA.
- This protein is excreted in the urine.
- Normally none or very little amount of this protein is found in the urine.
- This is recommended for the follow up of Transitional cell carcinoma of the urinary tract.
- This is a cheaper marker for the recurrence of bladder cancer.
- This is elevated in bladder cancer.
- NMP22 is a good screening test for the patient who is at greater risk to develop bladder cancer.
- NMP22 may be raised in the tumor involving ureter and renal pelvis.
- Urine sample:
- This protein is unstable in the urine if urine is not stabilized immediately, they can get a false result.
- Normal source 2:
- <10 units/mL.
Bladder tumor-associated Antigen (BTA)
- BTA are high molecular weight polypeptides.
- BTA presence in the urine may be due to :
- Involvement of the basement membrane in the tumor. OR
- Produced by the tumor.OR
- Combination of both.
- BTA test was positive in 40% of the cases on cystoscopy proved bladder tumor.
- While cytology gives only 17% positivity.
- BTA is a marker of a bladder tumor.
- But BTA is not a good screening test because this may be raised in other conditions like:
- Recent urologic surgery.
- Calculi.
- Urinary tract infection.
- But BTA is not a good screening test because this may be raised in other conditions like:
- Normal source 2:
- <14 units/mL
Genetic markers
- This is considered that multiple genetic alterations may lead to uncontrolled proliferation of the cells and result in cancers.
- This gene abnormality also gives rise to metastases.
- Evaluation of chromosomal changes may help to diagnose the cancers.
- There are two types of genes :
- Oncogene = these are the cell activation genes. Promote tumor formation.
- Suppressor gene = these genes are involved in the recognition and repair of damaged DNA.
- c-erb B-2 is also called an HER-2/neu gene.
Table of Oncogenes
Oncogene | Type of cancer |
---|---|
N-rs mutation | Acute myeloid leukemia, Neuroblastoma |
K-rs mutation | Leukemia, Lymphoma |
c-myc transduction | B and T cell Lymphoma, Small cell lung cancer |
c-erb B-2 amplification | Breast, Ovarian and GI tract cancers |
N-myc amplification | Neuroendocrine tumor |
bcl-2 | Leukemia, Lymphoma |
Suppressor gene
- This is studied that normal cell contains a gene which suppresses the expression of malignancy.
- The loss of the chromosome 5 gene leads to an increase in cell growth.
- Metastasis occurs with the loss of genes.
- The significance of detection of mutation in the tumor suppressor gene help in the diagnosis and prognosis of the tumor.
- This mutation of the suppressor gene also helps to predict susceptibility when the mutation is carried in the germline e.g. breast cancer gene BRCA1 and BRCA2.
Table of Suppressor gene:
Suppressor gene | Tumor |
---|---|
RB gene | Retinoblastoma |
p53 gene | Breast, colorectal, lung, renal, bladder, sarcoma |
BRCA1 | Neurofibromatosis, melanoma, breast |
BRCA2 | Breast |
Table of tumor markers
Test | Marker of tumor |
---|---|
Alpha-fetoprotein | Liver cell carcinoma |
Vanillylmandelic acid VMA | Pheochromocytoma and neuroblastoma |
beta – HCG | Trophoblastic tumors |
Liver alkaline phosphatase | liver metastasis, seminoma, and ovarian cancers |
Bone alkaline phosphatase | Osteogenic sarcoma and bone metastasis |
The various enzyme in different tumors:
Enzymes | Organs involved in tumor |
Alkaline phosphatase | Liver, bone, and sarcoma |
Amylase | Pancreas |
Aldolase | Liver |
Creatine kinase-BB | Breast, colon, ovary, prostate, and lung |
Gamma-glutamyltransferase | Liver |
Lactate dehydrogenase | Lymphomas, leukemias, liver and other organs |
5 nucleotidase | Liver |
Prostatic acid phosphatase | Prostate |
- Please see in Tumor marker parts 1, 2, and 3.