KRAS - zest. do oceny mutacji


 1. KRAS-RT50 - K-Ras Mutation Analysis Kit for Real-Time PCR (codons 12, 13, 61, 117 and 146 ) - 50 reactions

 2. KRBR-RT50 - K-Ras/B-Raf Mutation Analysis Panel Kit for Real-Time PCR (codons 12, 13, 61, 117 and 146 of KRAS and V600E of BRAF) - 50 reactions

 3. BRAF-RT50 - B-Raf V600E Mutation Analysis Kit for Real-Time PCR 50 reactions

 

KRAS/BRAF Mutations and Cancer

The KRAS gene encodes a small GTPase that plays a key role in transducing signals from the epidermal growth factor receptor (EGFR) to downstream effectors. KRAS mutations have been commonly found in several types of human malignancies, such as metastatic colorectal cancer (mCRC), lung adenocarcinoma and thyroid cancer. The most common mutations are found in codons codons 12, 13, 61, 117 and 146.

 

Several studies have demonstrated that tumors carrying any of these mutant forms of the KRAS gene are less likely to respond to anti-EGFR antibody therapy. The American Society of Clinical Oncology (ASCO) recently released its first Provisional Clinical Opinion (PCO) suggesting that all patients to be administered anti-EGFR monoclonal antibody therapy (e.g. cetuximab, panitumumab and erlotnib) should be screened for KRAS mutations.

 

Recent studies have also shown that not all mCRC patients with wild-type KRAS tumors respond to anti-EGFR therapy. This suggests that additional genes and/or pathways may be involved in the mechanism of resistance to these drugs. Mutations in BRAF, another downstream effector of the EGF-activated pathway, have been identified in up to 8% of mCRC tumors. Studies with mCRC patients have shown resistance to anti-EGFR therapy in patients with tumors expressing mutated BRAF. Those same individuals also had decreased progression-free (PFS) and overall (OS) survival when treated with EGFR antagonists.

 

These findings strongly suggest that screening for both KRAS and BRAF mutations is necessary to more accurately identify tumor cells that will not respond to anti-EGFR drugs.

This kit detects the following mutations in KRAS:

 

Exon

Mutation

Nucleotide Change

Amino Acid Change

Cosmic ID

2

G12A

c.35G>C

Glycine (G) to Alanine (A).

522

G12D

c.35G>A

Glycine (G) to Aspartic acid (D)

521

G12R

c.34G>C

Glycine (G) to Arginine (R)

518

G12C

c.34G>T

Glycine (G) to Cysteine (C)

516

G12S

c.34G>A

Glycine (G) to Serine (S)

517

G12V

c.35G>T

Glycine (G) to Valine (V)

520

G13D

c.38G>A

Glycine (G) to Aspartic acid (D)

532

3

Q61H

c.183A>C

Glutamine (Q) to Histidine (H)

554

Q61H

c.183A>T

Glutamine (Q) to Histidine (H)

555

Q61L

c.182A>T

Glutamine (Q) to Leucine (L)

553

Q61R

c.182A>G

Glutamine (Q) to Arginine (R)

552

4

K117N

c.351A>C

Lysine (K) to Asparagine (N)

19940

K117N

c.351A>T

Lysine (K) to Asparagine (N)

28519

K117R

c.350A>G

Lysine (K) to Arginine (R)

1178068

K117E

c.349A>G

Lysine (K) to Glutamic acid (E)

1360831

A146T

c.436G>A

Alanine (A) to Threonine (T)

19404

A146P

c.436G>C

Alanine (A) to Proline (P)

19905

A146V

c.437C>T

Alanine (A) to Valine (V)

19900

 

and BRAF:

Exon Mutation Nucleotide Change Amino Acid Change COSMIC ID
15 V600E c.1799T>A Valine (V) to Glutamic acid (E) 476

 

Testing Procedure and Analysis

EntroGen’s KRAS/BRAF mutation panel is a polymerase chain reaction (PCR)-based assay and uses allele-specific probes to identify the presence of mutations in KRAS codons 12, 13 and 61, as well as BRAF V600E. The testing procedure involves four (4) simple steps:

  • Isolation of DNA from tumor biopsies, paraffin-embedded sections (FFPE), fresh frozen tumors, or tumor cell lines.
  • Amplification of regions of the KRAS and BRAF genes using allele-specific probes.
  • Detection of amplification signal using real-time PCR instrument or gel documentation system.
  • Documentation and interpretation of results.

This test can be completed in approximately 2 hours from DNA to test result.

 

Equipment and Materials

This assay requires a real-time thermal cycler capable of detecting FAM and VIC fluorescence signals. This test includes reagents required for the PCR amplification and signal detection, as well as validated reaction controls. Columns and reagents for DNA isolation are not included.

 

Bibliography of studies using this product

Poster presented at the 20th National Pathology Congess, Turkey, September 2010. Comparison of K-RAS Mutation Analysis Tests.

 

Veysel Sabri Hançer, Gökhan Demir, İlknur Türkmen, Murat Büyükdoğan, Nuray Başsüllü, Tuncay Altuğ, Reyhan Diz-Küçükkaya, Gülen Bülbül-Doğusoy.

 

Hancer VS, Buyukdogan M, Türkmen I, Bassullu N, Altug T, Diz-Kucukkaya R, Bulbul-Dogusoy G, Demir G. Comparison of KRAS Mutation Tests in Colorectal Cancer Patients. Genet Test Mol Biomarkers. 2011 Jun 23.

Pubmed ID 21699410