User login
Mutations in the RRAGC gene appear to be an “excellent candidate for therapeutic targeting” in follicular lymphoma (FL), according to investigators.
They analyzed mutations found in tumors with multiple relapses of FL without transformation to diffuse large B-cell lymphoma.
And they found that one commonly mutated gene encodes the protein RagC, which is essential for activating the amino-acid sensing mTORC1 pathway.
Although mutations in genes in the mTORC1 pathway have been associated with various cancers, this is the first time a genetic mutation in any of the 4 Rag proteins has been identified in malignancy.
“One of the mutations that we have identified allows follicular lymphoma tumors to turn on growth signals regardless of whether nutrients are available, thereby evading normal restrictions on its growth,” said study author Jessica Okosun, MB BChir, PhD, of Barts Cancer Institute at Queen Mary University of London in the UK.
“Remarkably, the mutations we have discovered have not been seen in other cancer types. However, drugs that directly target this nutrient-sensing mechanism are currently used to treat other types of cancer and may benefit patients with follicular lymphoma.”
Dr Okosun and her colleagues reported these findings in a letter to Nature Genetics.
In experiments with cell lines, the investigators found that expression of the mutated RagC proteins activate mTORC1 signaling in the absence of amino acids and increase binding to an important part of the mTORC1 complex, consistent with the established role of RagC in the mTORC1 pathway.
Because this research was performed exclusively in cell lines, the investigators have not yet deciphered the mutations’ mechanistic effect in patients. However, study author Rachel Wolfson, of the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology in Cambridge, Massachusetts, said there are clues to the mutations’ significance.
“mTORC1 is linked to cell growth, so it is not surprising that activation of the pathway could lead to some growth advantage for cancer cells,” Wolfson said. “But it leads to an interesting question: When is it a proliferative advantage versus a disadvantage to no longer be able to accurately sense amino acid levels? That is something we would need to investigate further, likely in vivo.”
The investigators would also like to know how the drug rapamycin affects FL with RagC mutations. Rapamycin binds to mTORC1 and inhibits its activity. If the drug interferes with mTORC1 dysregulation caused by RagC mutations, perhaps the drug could be used in FL treatment.
“If so, maybe these RagC mutations could be used as biomarkers to predict sensitivity to rapamycin treatment in follicular lymphoma patients,” Wolfson said. “That would be very exciting, and it’s something that should be investigated further.” 
Mutations in the RRAGC gene appear to be an “excellent candidate for therapeutic targeting” in follicular lymphoma (FL), according to investigators.
They analyzed mutations found in tumors with multiple relapses of FL without transformation to diffuse large B-cell lymphoma.
And they found that one commonly mutated gene encodes the protein RagC, which is essential for activating the amino-acid sensing mTORC1 pathway.
Although mutations in genes in the mTORC1 pathway have been associated with various cancers, this is the first time a genetic mutation in any of the 4 Rag proteins has been identified in malignancy.
“One of the mutations that we have identified allows follicular lymphoma tumors to turn on growth signals regardless of whether nutrients are available, thereby evading normal restrictions on its growth,” said study author Jessica Okosun, MB BChir, PhD, of Barts Cancer Institute at Queen Mary University of London in the UK.
“Remarkably, the mutations we have discovered have not been seen in other cancer types. However, drugs that directly target this nutrient-sensing mechanism are currently used to treat other types of cancer and may benefit patients with follicular lymphoma.”
Dr Okosun and her colleagues reported these findings in a letter to Nature Genetics.
In experiments with cell lines, the investigators found that expression of the mutated RagC proteins activate mTORC1 signaling in the absence of amino acids and increase binding to an important part of the mTORC1 complex, consistent with the established role of RagC in the mTORC1 pathway.
Because this research was performed exclusively in cell lines, the investigators have not yet deciphered the mutations’ mechanistic effect in patients. However, study author Rachel Wolfson, of the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology in Cambridge, Massachusetts, said there are clues to the mutations’ significance.
“mTORC1 is linked to cell growth, so it is not surprising that activation of the pathway could lead to some growth advantage for cancer cells,” Wolfson said. “But it leads to an interesting question: When is it a proliferative advantage versus a disadvantage to no longer be able to accurately sense amino acid levels? That is something we would need to investigate further, likely in vivo.”
The investigators would also like to know how the drug rapamycin affects FL with RagC mutations. Rapamycin binds to mTORC1 and inhibits its activity. If the drug interferes with mTORC1 dysregulation caused by RagC mutations, perhaps the drug could be used in FL treatment.
“If so, maybe these RagC mutations could be used as biomarkers to predict sensitivity to rapamycin treatment in follicular lymphoma patients,” Wolfson said. “That would be very exciting, and it’s something that should be investigated further.”
Mutations in the RRAGC gene appear to be an “excellent candidate for therapeutic targeting” in follicular lymphoma (FL), according to investigators.
They analyzed mutations found in tumors with multiple relapses of FL without transformation to diffuse large B-cell lymphoma.
And they found that one commonly mutated gene encodes the protein RagC, which is essential for activating the amino-acid sensing mTORC1 pathway.
Although mutations in genes in the mTORC1 pathway have been associated with various cancers, this is the first time a genetic mutation in any of the 4 Rag proteins has been identified in malignancy.
“One of the mutations that we have identified allows follicular lymphoma tumors to turn on growth signals regardless of whether nutrients are available, thereby evading normal restrictions on its growth,” said study author Jessica Okosun, MB BChir, PhD, of Barts Cancer Institute at Queen Mary University of London in the UK.
“Remarkably, the mutations we have discovered have not been seen in other cancer types. However, drugs that directly target this nutrient-sensing mechanism are currently used to treat other types of cancer and may benefit patients with follicular lymphoma.”
Dr Okosun and her colleagues reported these findings in a letter to Nature Genetics.
In experiments with cell lines, the investigators found that expression of the mutated RagC proteins activate mTORC1 signaling in the absence of amino acids and increase binding to an important part of the mTORC1 complex, consistent with the established role of RagC in the mTORC1 pathway.
Because this research was performed exclusively in cell lines, the investigators have not yet deciphered the mutations’ mechanistic effect in patients. However, study author Rachel Wolfson, of the Whitehead Institute for Biomedical Research and Massachusetts Institute of Technology in Cambridge, Massachusetts, said there are clues to the mutations’ significance.
“mTORC1 is linked to cell growth, so it is not surprising that activation of the pathway could lead to some growth advantage for cancer cells,” Wolfson said. “But it leads to an interesting question: When is it a proliferative advantage versus a disadvantage to no longer be able to accurately sense amino acid levels? That is something we would need to investigate further, likely in vivo.”
The investigators would also like to know how the drug rapamycin affects FL with RagC mutations. Rapamycin binds to mTORC1 and inhibits its activity. If the drug interferes with mTORC1 dysregulation caused by RagC mutations, perhaps the drug could be used in FL treatment.
“If so, maybe these RagC mutations could be used as biomarkers to predict sensitivity to rapamycin treatment in follicular lymphoma patients,” Wolfson said. “That would be very exciting, and it’s something that should be investigated further.”