Melanoma, TP53, R273G (c.817C>G)

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Expand Collapse Melanoma  - General Description Skin cancer is a malignant tumor that grows in the skin cells and accounts for more than 50 percent of all cancers. There are generally three different types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

Basal cell carcinoma and squamous cell carcinoma usually appear on sun-exposed areas of the body. Prognosis is generally good and both of these cancer types can usually be effectively treated through surgery, with a minority of cases requiring radiation treatment.

Melanoma is the most aggressive form of skin cancer and arises in the cells that produce pigment (color) in the skin. BRAF is the gene that is most frequently activated by mutation in this malignancy and the common BRAF V600E and V600K mutations have been associated with a more aggressive clinical course and shorter survival. Vemurafenib is a new and effective FDA-approved targeted agent that is available to treat unresectable or metastatic melanoma based on the presence of a BRAF V600E mutation. Preclinical data has indicated that the rare BRAF V600R mutation may also be sensitive to vemurafenib. Also, the BRAF L597R mutation has been found to confer sensitivity to downstream MEK inhibitors. Most recently, the combination of the BRAF inhibitor dabrafenib with the MEK inhibitor trametinib was approved by FDA for the treatment of patients with BRAF V600E or V600K mutations. While less frequent, mutations in cancer genes such as NRAS, MEK, PTEN, PIK3CA and KIT may provide opportunities for enrollment into ongoing clinical trials.

Skin cancer is a malignant tumor that grows in the skin cells and accounts for more than 50 percent of all cancers. There are generally three different types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

Basal cell carcinoma and squamous cell carcinoma usually appear on sun-exposed areas of the body. Prognosis is generally good and both of these cancer types can usually be effectively treated through surgery, with a minority of cases requiring radiation treatment.

Melanoma is the most aggressive form of skin cancer and arises in the cells that produce pigment (color) in the skin. BRAF is the gene that is most frequently activated by mutation in this malignancy and the common BRAF V600E and V600K mutations have been associated with a more aggressive clinical course and shorter survival. Vemurafenib is a new and effective FDA-approved targeted agent that is available to treat unresectable or metastatic melanoma based on the presence of a BRAF V600E mutation. Preclinical data has indicated that the rare BRAF V600R mutation may also be sensitive to vemurafenib. Also, the BRAF L597R mutation has been found to confer sensitivity to downstream MEK inhibitors. Most recently, the combination of the BRAF inhibitor dabrafenib with the MEK inhibitor trametinib was approved by FDA for the treatment of patients with BRAF V600E or V600K mutations. While less frequent, mutations in cancer genes such as NRAS, MEK, PTEN, PIK3CA and KIT may provide opportunities for enrollment into ongoing clinical trials.

Skin cancer is a malignant tumor that grows in the skin cells and accounts for more than 50 percent of all cancers. There are generally three different types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

Basal cell carcinoma and squamous cell carcinoma usually appear on sun-exposed areas of the body. Prognosis is generally good and both of these cancer types can usually be effectively treated through surgery, with a minority of cases requiring radiation treatment.

Melanoma is the most aggressive form of skin cancer and arises in the cells that produce pigment (color) in the skin. BRAF is the gene that is most frequently activated by mutation in this malignancy and the common BRAF V600E and V600K mutations have been associated with a more aggressive clinical course and shorter survival. Vemurafenib is a new and effective FDA-approved targeted agent that is available to treat unresectable or metastatic melanoma based on the presence of a BRAF V600E mutation. Preclinical data has indicated that the rare BRAF V600R mutation may also be sensitive to vemurafenib. Also, the BRAF L597R mutation has been found to confer sensitivity to downstream MEK inhibitors. Most recently, the combination of the BRAF inhibitor dabrafenib with the MEK inhibitor trametinib was approved by FDA for the treatment of patients with BRAF V600E or V600K mutations. While less frequent, mutations in cancer genes such as NRAS, MEK, PTEN, PIK3CA and KIT may provide opportunities for enrollment into ongoing clinical trials.

Skin cancer is a malignant tumor that grows in the skin cells and accounts for more than 50 percent of all cancers. There are generally three different types of skin cancer: basal cell carcinoma, squamous cell carcinoma and melanoma.

Basal cell carcinoma and squamous cell carcinoma usually appear on sun-exposed areas of the body. Prognosis is generally good and both of these cancer types can usually be effectively treated through surgery, with a minority of cases requiring radiation treatment.

Melanoma is the most aggressive form of skin cancer and arises in the cells that produce pigment (color) in the skin. BRAF is the gene that is most frequently activated by mutation in this malignancy and the common BRAF V600E and V600K mutations have been associated with a more aggressive clinical course and shorter survival. Vemurafenib is a new and effective FDA-approved targeted agent that is available to treat unresectable or metastatic melanoma based on the presence of a BRAF V600E mutation. Preclinical data has indicated that the rare BRAF V600R mutation may also be sensitive to vemurafenib. Also, the BRAF L597R mutation has been found to confer sensitivity to downstream MEK inhibitors. Most recently, the combination of the BRAF inhibitor dabrafenib with the MEK inhibitor trametinib was approved by FDA for the treatment of patients with BRAF V600E or V600K mutations. While less frequent, mutations in cancer genes such as NRAS, MEK, PTEN, PIK3CA and KIT may provide opportunities for enrollment into ongoing clinical trials.

PubMed ID's
21343559, 22798288, 20551065
Expand Collapse TP53  - General Description
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The p53 (TP53) gene produces a protein, P53 which has many complex functions within the cell. It has been called the “guardian of the genome” for reasons that have to do with these complex functions. Normal, non-cancerous cells have tightly regulated pathways that control cell growth, mediating cessation of growth or even cell death when circumstances warrant it. P53 is at the center of these pathways, acting as a “tumor suppressor” in responding to circumstances in the cell that require a cessation of growth. Perhaps for this reason, P53 is one of the most commonly mutated genes across all cancer types.

P53 itself regulates the expression of several genes that are involved in growth arrest or “cell cycle arrest”. Growth arrest is important for stopping the cell from normal growth and cell division so that if, for instance, there has been damage to the DNA from UV irradiation or some other insult causing DNA damage, the cessation of the cell cycle allows DNA repair to take place before the cell resumes growth. If the damage to the DNA is too extensive to repair, or if other factors such as oncogenic stress impact the cell, P53 then has roles in other processes that are part of the cell’s repertoire of responses. These include processes such as apoptosis (programmed cell death), senescence (irreversible cell cycle arrest), autophagy (regulated destruction of selected proteins within the cell, leading to cell death), and some important metabolic changes in the cell (see graphic above, adapted with permission).

P53 is itself acted upon by proteins in the cell that detect DNA damage or oncogenic stress (see graphic depicting P53 at the center of a number of cellular responses). In the case of DNA damage to the cell, P53 is acted upon by a protein called ATM and another designated CHK2 (see glossary for more information). These proteins activate P53 to regulate the changes that will cause growth arrest. Interestingly, these two genes themselves are found to be mutated and have altered function in certain cancers. The fact that both P53 and the genes that trigger P53’s response and initiation of growth arrest are mutated in some cancers highlights the importance of P53 to normal cell growth. P53 is found to be mutated in over half of cancers studied, including ovarian cancer, colon and esophageal cancer, and many other types of cancer. Because p53 plays so many complex roles in the cell, we do not depict it in a simple graphic as we have with other proteins on this web site in which genetic alterations have been found in specific tumors that lead to dysregulation of these proteins. Rather, P53 as a negative regulator of cell growth under important circumstances plays this role at the center of a complex network of pathways within the cell. Many of the proteins involved in the pathways that regulate P53 and its responses are also found to be genetically altered in some cancers.

As we have seen, the P53 protein has many functions in the cell, and because of these many roles, its location in the nucleus or cytoplasm varies, depending on the function and when it exerts its effect during the cell cycle. One important protein that regulates P53 is called HDM2/MDM2, depicted in the graphic above. The HDM2/MDM2 protein contains a p53 binding domain, and once bound to p53, it inhibits the activation of the P53 protein, and thereby prevents P53 from regulating growth arrest, even when there is damage to the DNA. Some cancers have been found to overexpress HDM2/MDM2, meaning there is an excess of the protein which binds to P53, preventing it from exerting its important role in regulating growth arrest. Cell division that occurs despite damage to the DNA can lead to cancer. Interestingly, those cancers that have been found to over-express HDM2/MDM2 typically are not found to have p53 mutations. This provides scientists with evidence that by whatever means, either through increasing the amount of the P53 inhibitor HDM2/MDM2, or, through mutations in P53 that prevent the normal activities of the protein, the normal function of P53 is important in preventing cancer. MDM2 was named after its discovery in studies on laboratory mice. The human version of the gene is designated HumanDM2, or HDM2. Genetic alterations leading to over-expression of MDM2 are observed most commonly in sarcomas, but have also been observed in endometrial cancer, colon cancer, and stomach cancer.

Source: Molecular Genetics of Cancer, Second Edition
Chapter No. 2, Section No. 12
Leif W. Ellisen, MD, PhD
The p53 (TP53) gene produces a protein, P53 which has many complex functions within the cell. It has been called the “guardian of the genome” for reasons that have to do with these complex functions. Normal, non-cancerous cells have tightly regulated pathways that control cell growth, mediating cessation of growth or even cell death when circumstances warrant it. P53 is at the center of these pathways, acting as a “tumor suppressor” in responding to circumstances in the cell that require a cessation of growth. Perhaps for this reason, P53 is one of the most commonly mutated genes across all cancer types.

P53 itself regulates the expression of several genes that are involved in growth arrest or “cell cycle arrest”. Growth arrest is important for stopping the cell from normal growth and cell division so that if, for instance, there has been damage to the DNA from UV irradiation or some other insult causing DNA damage, the cessation of the cell cycle allows DNA repair to take place before the cell resumes growth. If the damage to the DNA is too extensive to repair, or if other factors such as oncogenic stress impact the cell, P53 then has roles in other processes that are part of the cell’s repertoire of responses. These include processes such as apoptosis (programmed cell death), senescence (irreversible cell cycle arrest), autophagy (regulated destruction of selected proteins within the cell, leading to cell death), and some important metabolic changes in the cell (see graphic above, adapted with permission).

P53 is itself acted upon by proteins in the cell that detect DNA damage or oncogenic stress (see graphic depicting P53 at the center of a number of cellular responses). In the case of DNA damage to the cell, P53 is acted upon by a protein called ATM and another designated CHK2 (see glossary for more information). These proteins activate P53 to regulate the changes that will cause growth arrest. Interestingly, these two genes themselves are found to be mutated and have altered function in certain cancers. The fact that both P53 and the genes that trigger P53’s response and initiation of growth arrest are mutated in some cancers highlights the importance of P53 to normal cell growth. P53 is found to be mutated in over half of cancers studied, including ovarian cancer, colon and esophageal cancer, and many other types of cancer. Because p53 plays so many complex roles in the cell, we do not depict it in a simple graphic as we have with other proteins on this web site in which genetic alterations have been found in specific tumors that lead to dysregulation of these proteins. Rather, P53 as a negative regulator of cell growth under important circumstances plays this role at the center of a complex network of pathways within the cell. Many of the proteins involved in the pathways that regulate P53 and its responses are also found to be genetically altered in some cancers.

As we have seen, the P53 protein has many functions in the cell, and because of these many roles, its location in the nucleus or cytoplasm varies, depending on the function and when it exerts its effect during the cell cycle. One important protein that regulates P53 is called HDM2/MDM2, depicted in the graphic above. The HDM2/MDM2 protein contains a p53 binding domain, and once bound to p53, it inhibits the activation of the P53 protein, and thereby prevents P53 from regulating growth arrest, even when there is damage to the DNA. Some cancers have been found to overexpress HDM2/MDM2, meaning there is an excess of the protein which binds to P53, preventing it from exerting its important role in regulating growth arrest. Cell division that occurs despite damage to the DNA can lead to cancer. Interestingly, those cancers that have been found to over-express HDM2/MDM2 typically are not found to have p53 mutations. This provides scientists with evidence that by whatever means, either through increasing the amount of the P53 inhibitor HDM2/MDM2, or, through mutations in P53 that prevent the normal activities of the protein, the normal function of P53 is important in preventing cancer. MDM2 was named after its discovery in studies on laboratory mice. The human version of the gene is designated HumanDM2, or HDM2. Genetic alterations leading to over-expression of MDM2 are observed most commonly in sarcomas, but have also been observed in endometrial cancer, colon cancer, and stomach cancer.

Source: Molecular Genetics of Cancer, Second Edition
Chapter No. 2, Section No. 12
Leif W. Ellisen, MD, PhD
Expand Collapse R273G (c.817C>G)  in TP53
The TP53 R273G mutation arises from a single nucleotide change (c.817C>G) and results in an amino acid substitution of the arginine (R) at position 273 by a glycine (G).
The TP53 R273G mutation arises from a single nucleotide change (c.817C>G) and results in an amino acid substitution of the arginine (R) at position 273 by a glycine (G).

The p53 pathway is frequently disrupted in melanoma, but only a small fraction of tumors harbor mutations in the TP53 gene. Other mechanisms implicated in p53 inactivation include mutations within the CDKN2A locus (involved in familial melanoma) and increased expression of MDM2.

TP53 mutations have been associated with sun-exposed lesions and do not provide meaningful insight on prognosis.

Preclinical laboratory studies have suggested that TP53 mutations are linked to an impaired apoptotic response and resistance to chemotherapeutic drugs such as cisplatin.

The p53 pathway is frequently disrupted in melanoma, but only a small fraction of tumors harbor mutations in the TP53 gene. Other mechanisms implicated in p53 inactivation include mutations within the CDKN2A locus (involved in familial melanoma) and increased expression of MDM2.

TP53 mutations have been associated with sun-exposed lesions and do not provide meaningful insight on prognosis.

Preclinical laboratory studies have suggested that TP53 mutations are linked to an impaired apoptotic response and resistance to chemotherapeutic drugs such as cisplatin.

PubMed ID's
12789286, 17443002, 9495365, 10070891, 9508372, 12789290
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Your Matched Clinical Trials

Trial Matches: (D) - Disease, (G) - Gene, (M) - Mutation
Trial Status: Showing Results: 1-10 of 27 Per Page:
123Next »
Protocol # Title Location Status Match
NCT02335918 A Dose Escalation and Cohort Expansion Study of Anti-CD27 (Varlilumab) and Anti-PD-1 (Nivolumab) in Advanced Refractory Solid Tumors A Dose Escalation and Cohort Expansion Study of Anti-CD27 (Varlilumab) and Anti-PD-1 (Nivolumab) in Advanced Refractory Solid Tumors MGH Open D
NCT02637531 A Dose-Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of IPI-549 A Dose-Escalation Study to Evaluate the Safety, Tolerability, Pharmacokinetics, and Pharmacodynamics of IPI-549 MGH Open D
NCT02327169 A Phase 1B Study of MLN2480 in Combination With MLN0128 or Alisertib, or Paclitaxel, or Cetuximab, or Irinotecan in Adult Patients With Advanced Nonhematologic Malignancies A Phase 1B Study of MLN2480 in Combination With MLN0128 or Alisertib, or Paclitaxel, or Cetuximab, or Irinotecan in Adult Patients With Advanced Nonhematologic Malignancies MGH Open D
NCT02110355 A Phase 1b/2a Study Evaluating AMG 232 in Metastatic Melanoma A Phase 1b/2a Study Evaluating AMG 232 in Metastatic Melanoma MGH Open D
NCT01714739 A Study of an Anti-KIR Antibody in Combination With an Anti-PD1 Antibody in Patients With Advanced Solid Tumors A Study of an Anti-KIR Antibody in Combination With an Anti-PD1 Antibody in Patients With Advanced Solid Tumors MGH Open D
NCT01325441 A Study of BBI608 Administered With Paclitaxel in Adult Patients With Advanced Malignancies A Study of BBI608 Administered With Paclitaxel in Adult Patients With Advanced Malignancies MGH Open D
NCT02228811 A Study of DCC-2701 in Participants With Advanced Solid Tumors A Study of DCC-2701 in Participants With Advanced Solid Tumors MGH Open D
NCT02082210 A Study of LY2875358 in Combination With Ramucirumab (LY3009806) in Participants With Advanced Cancer A Study of LY2875358 in Combination With Ramucirumab (LY3009806) in Participants With Advanced Cancer MGH Open D
NCT02857270 A Study of LY3214996 Administered Alone or in Combination With Other Agents in Participants With Advanced/Metastatic Cancer A Study of LY3214996 Administered Alone or in Combination With Other Agents in Participants With Advanced/Metastatic Cancer MGH Open D
NCT02320058 A Study to Evaluate Safety and Effectiveness in Patients With Melanoma That Has Spread to the Brain Treated With Nivolumab in Combination With Ipilimumab Followed by Nivolumab by Itself A Study to Evaluate Safety and Effectiveness in Patients With Melanoma That Has Spread to the Brain Treated With Nivolumab in Combination With Ipilimumab Followed by Nivolumab by Itself MGH Open D
Trial Status: Showing Results: 1-10 of 27 Per Page:
123Next »
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