Navigation Links
Uncommon BRAF mutation in melanoma sensitive to MEK inhibitor drug therapy
Date:7/16/2012

An uncommon mutation of the BRAF gene in melanoma patients has been found to respond to MEK inhibitor drugs, providing a rationale for routine screening and therapy in melanoma patients who harbor the BRAF L597 mutation.

The new study by co-first-authors Kimberly Brown Dahlman, Ph.D., Junfeng Xia, Ph.D., and Katherine Hutchinson, B.S., Vanderbilt-Ingram Cancer Center (VICC), Nashville, Tenn., was published online July 14 in Cancer Discovery. The research was led by co-senior authors William Pao, M.D., Ph.D., Jeffrey Sosman, M.D., and Zhongming Zhao, Ph.D., VICC, and Antoni Ribas, M.D., Jonsson Comprehensive Cancer Center, UCLA, Los Angeles, Calif.

Mutations in BRAF V600E or KIT are common in about 40 percent to 50 percent of melanomas, and drugs that block or inhibit BRAF V600E were recently approved for treatment of melanoma patients with these mutations. However, there has been no effective treatment for patients with wildtype (WT) melanoma that is negative for these driver mutations.

To uncover other potentially targetable mutations, the investigators studied the tumor from a 75-year-old patient with an aggressive form of melanoma which was negative for the BRAF V600E mutation. They performed whole genome sequencing on the tumor, along with DNA from matched blood, and confirmed a mutation at BRAF L597.

To determine how many similar mutations might be overlooked by assessing only the BRAF V600 position, they analyzed the mutational status of 49 additional tumor samples negative for V600, as well as recurrent mutations in NRAS and KIT. Two of the tumors (4 percent) were found to have BRAF L597 mutations and a third tumor harbored a BRAF K601E mutation.

BRAF L597 and K601 are adjacent to V600. Since V600 mutants are sensitive to both BRAF and MEK inhibitor drugs, the investigators tested whether the BRAF inhibitor drug vemurafenib and a MEK inhibitor drug could inhibit cell proliferation signals induced by these mutants in cell lines. The MEK inhibitor led to a dramatic shut down of signaling, suggesting that tumors harboring BRAF L597 and K601 mutations might benefit from treatment with MEK inhibitors.

Confirming this hypothesis, a 69-year-old patient with metastatic melanoma harboring a BRAF L597S mutation experienced significant disease shrinkage after two cycles on therapy with a MEK inhibitor drug called TAK-733, currently in Phase I clinical trials. The patient was disease progression-free after more than 24 weeks.

The authors believe these data demonstrate that BRAF L597 mutations have clinical significance in melanoma. Further study is needed to confirm these findings.


'/>"/>

Contact: Dagny Stuart
dagny.stuart@vanderbilt.edu
615-936-7245
Vanderbilt University Medical Center
Source:Eurekalert

Related medicine news :

1. KRAS gene mutation and amplification status affects sensitivity to antifolate therapy
2. Researchers Find Gene Mutations That May Be a Key to Autism
3. Mayo Clinic breast cancer study finds new type of mutation
4. Scientists make breakthrough in bile duct cancer with discovery of new gene mutations
5. Cancer may require simpler genetic mutations than previously thought
6. Mutations impair childhood growth and development by disrupting organization of chromosome pairs
7. Study sheds new light on role of genetic mutations in colon cancer development
8. Mutations in JAK3 gene identified in subtype of lymphoma provide potential drug target
9. Study finds new gene mutations that lead to enlarged brain size, cancer, autism, epilepsy
10. Gene Mutation Linked to Facial, Skull Abnormalities
11. Mutation in gene IDH a possible target for AML treatment
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:6/24/2016)... ... June 24, 2016 , ... The ... in Dallas that it will receive two significant new grants to support its ... PHA marked its 25th anniversary by recognizing patients, medical professionals and scientists for ...
(Date:6/24/2016)... CA (PRWEB) , ... June 24, 2016 , ... ... is now offering micro-osteoperforation for accelerated orthodontic treatment. Dr. Cheng has extensive experience ... Damon brackets , AcceleDent, and accelerated osteogenic orthodontics. , Micro-osteoperforation is ...
(Date:6/24/2016)... ... 2016 , ... Topical BioMedics, Inc, makers of Topricin and MyPainAway Pain Relief Products, join The ... raise to $12 an hour by 2020 and then adjusting it yearly to increase at ... the minimum wage, assure the wage floor does not erode again, and make future increases ...
(Date:6/24/2016)... (PRWEB) , ... June 24, 2016 , ... ... today at the Clinical Decision Making in Emergency Medicine conference in Ponte Vedra ... authored journal articles published in Emergency Medicine Practice and Pediatric Emergency ...
(Date:6/24/2016)... ... June 24, 2016 , ... Puradigm® & Innovative Solutions today ... cultivation and processing operations at its production facility, and opened its first two ... the manufacturer of a complete system of proactive air and surface purification solutions ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... , June 24, 2016 ... appointment of Dr. Edward Futcher to ... Director, effective June 23, 2016.Dr. Futcher was also ... and Governance Committees.  As a non-executive member of ... expertise and strategic counsel to VolitionRx in connection ...
(Date:6/23/2016)... Calif. , June 23, 2016 Any dentist ... many challenges of the current process. Many of them do ... of the technical difficulties and high laboratory costs involved. And ... to offer it at such a high cost that the ... it. Dr. Parsa Zadeh , founder of ...
(Date:6/23/2016)... 2016 Research and Markets has announced ... Analysis 2016 - Forecast to 2022" report to their ... contains up to date financial data derived from varied research ... trends with potential impact on the market during the next ... which comprises of sub markets, regional and country level analysis. ...
Breaking Medicine Technology: