Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: EC:2.4.2.30 (PARP)
13,611 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Epithelial ovarian cancer is the most lethal of the gynecologic malignancies, largely due to the advanced stage at diagnosis in most patients. Screening strategies using ultrasound and the cancer antigen (CA) 125 tumor marker are currently under study and may lower stage at diagnosis but have not yet been shown to improve survival. Women who have inherited a deleterious mutation in the BRCA1 or BRCA2 gene and those with the Lynch syndrome (hereditary nonpolyposis colorectal cancer) have the highest risk of developing ovarian cancer but account for only approximately 10% of those with the disease. Other less common and less well-defined genetic syndromes may increase the risk of ovarian cancer, but their contribution to genetic risk is small. A clear etiology for sporadic ovarian cancer has not been identified, but risk is affected by reproductive and hormonal factors. Surgery has a unique role in ovarian cancer, as it is used not only for diagnosis and staging but also therapeutically, even in patients with widely disseminated, advanced disease. Ovarian cancer is highly sensitive to chemotherapy drugs, particularly the platinum agents, and most patients will attain a remission with initial treatment. Recent advances in the delivery of chemotherapy using the intraperitoneal route have further improved survival after initial therapy. Although the majority of ovarian cancer patients will respond to initial chemotherapy, most will ultimately develop disease recurrence. Chemotherapy for recurrent disease includes platinum-based, multiagent regimens for women whose disease recurs more than 6 to 12 months after the completion of initial therapy and sequential single agents for those whose disease recurs earlier. New targeted biologic agents, particularly those involved with the vascular endothelial growth factor pathway and those targeting the poly (ADP-ribose) polymerase (PARP) enzyme, hold great promise for improving the outcome of ovarian cancer.
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PMID:Recent progress in the diagnosis and treatment of ovarian cancer. 2152 30

Practice changes in cancer genetic counseling have occurred to meet the demand for cancer genetic services. As cancer genetics continues to impact not only prevention strategies but also treatment decisions, current cancer genetic counseling models will need to be tailored to accommodate emerging clinical indications. These clinical indications include: surgical prophylactic bilateral mastectomy candidates, PARP-inhibitor candidates, patients with abnormal tumor screening results for Lynch syndrome, and post-test counseling patients (after genetic testing is ordered by another healthcare provider). A more personalized, multidisciplinary approach to selecting the best framework, for a given clinical indication, may become increasingly necessary in this era of personalized medicine.
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PMID:The evolution of personalized cancer genetic counseling in the era of personalized medicine. 2241 76

Human cells have numerous repair mechanisms to counteract various insults incurred on the DNA. Any mutation in these repair mechanisms can lead to accumulation of DNA errors and carcinogenesis. This review aims to discuss the therapeutic options in the two most common DNA repair deficient cancer syndromes, namely Lynch syndrome (hereditary non-polyposis colorectal cancer) and breast cancer susceptibility gene (BRCA) associated ovarian and breast cancer. Deficiency in DNA repair mechanisms renders these tumors with increased sensitivity to platinum agents. There has been increasing amount of information on the utility of the defects in DNA repair as targets for cancer therapy in these syndromes. Novel therapies like poly (ADP-ribose) polymerase (PARP) inhibitors are one of such example where the induction of double stranded breaks in DNA leads to tumoricidal effect in patients with homologous DNA repair deficiency. Interestingly, patients with DNA repair deficiencies tend to have a more favorable prognosis than sporadic malignancies. In microsatellite high colorectal cancer patients, this has been attributed to increased recruitment of CD8+ T lymphocytes in tumor microenvironment. However, these tumors are able to limit the host immune response by activation of immune checkpoints that seem like attractive targets of therapy in the future.
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PMID:Hereditary cancer syndromes: utilizing DNA repair deficiency as therapeutic target. 2687 19

Development of molecular targeted drugs has achieved remarkable improvement of systemic cancer therapy. Recently, the several molecular targeted drugs have become available which associated with the status of responsible genes for hereditary cancer syndrome. These drugs would allow to establish specific strategy for hereditary cancer syndrome or sporadic cancers with similar biological phenotype with hereditary cancer. Genetic tests for the diagnosis of hereditary cancer syndrome will have the meaning of biomarker for predicting the efficacy of these molecular targeted drugs. This review summarized the molecular targeted drugs including immune checkpoint inhibitors with potential effects for hereditary cancer syndrome, such as anti-PD-1 antibody for Lynch syndrome, PARP inhibitor for hereditary breast and ovarian cancer syndrome, multi-kinase inhibitor for multiple endocrine neoplasia type 2.
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PMID:[Molecular Targeted Therapies for Hereditary Cancer Syndrome]. 2965 Aug 9

Choosing the optimal therapy for a patient's cancer has long been based on whether the cancer demonstrates a predictive marker of efficacy. The U.S. Food and Drug Administration (FDA) has now approved use of a targeted therapy based solely on tumor molecular markers (pembrolizumab for tumors with deficient mismatch repair [MMR] and high microsatellite instability [MSI]) and approved another therapy based solely on a germline mutation as the predictive marker of benefit (olaparib for BRCA carriers with ovarian or breast cancer) [New Engl J Med 2017;377:1409-1412, N Engl J Med 2012;366:1382-1392, N Eng J Med 2017;377:523-533].Here, a patient is presented with a molecular diagnosis of Lynch syndrome and with breast cancer. Yet the breast cancer showed proficient expression of the same MMR gene found to be mutated in her germline testing. The case underscores the importance of tumor testing for MMR and MSI and of not assuming that the tumor is related to the Lynch syndrome rather than being sporadic. This is particularly true in patients with cancers (e.g., breast cancer) whose association with Lynch syndrome is not well established.The case presented also underscores the importance of considering next-generation sequencing of the tumor when the therapies approved are based on a germline mutation being the predictive marker. For example, the FDA-approved use of the PARP inhibitor olaparib is for ovarian or breast cancers in patients harboring a BRCA germline mutation [N Engl J Med 2012;366:1382-1392, N Eng J Med 2017;377:523-533]. Yet patients with tumors lacking BRCA loss of heterozygosity (LOH) or lacking other evidence of probable loss of normal BRCA gene product expression might be less likely to benefit from PARP inhibitor therapy, because the efficacy of PARP inhibitor therapy in patients with germline BRCA mutations would likely be predicated upon BRCA LOH in their tumors. KEY POINTS: Cancers in patients with germline mutations may be sporadic and unrelated to the germline mutation.Lynch syndrome is due to a germline mutated mismatch repair (MMR) gene. Cancers resulting from the germline MMR gene mutation as the predisposing event would be expected to be MMR deficient (dMMR) and microsatellite instability high (MSI-H). Sporadic cancers in patients with Lynch syndrome would be expected to be MMR proficient or microsatellite stable.Pembrolizumab is only approved for solid tumors demonstrating dMMR/MSI-H. Thus, whether the cancer tissue of origin is clearly associated with Lynch syndrome or not yet clearly established as a Lynch syndrome-related cancer (e.g., breast cancer), establishing the tumor to be dMMR/MSI-H is necessary to predict possible benefit and endorse the use of pembrolizumab.Ovarian cancers that develop in BRCA germline mutation carriers are so often related to the inherited mutated BRCA as the predisposing factor that testing the tumor for the footprint of BRCA-related ovarian cancer (BRCA loss of heterozygosity) is not necessary for use of the PARP inhibitor therapy olaparib. Future studies that include tumor evaluation for normal BRCA expression or surrogates of normal BRCA gene product expression might help determine which patients harboring a germline BRCA mutation are most likely to benefit from PARP inhibitor therapy.
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PMID:The Importance of Distinguishing Sporadic Cancers from Those Related to Cancer Predisposing Germline Mutations. 2986 45

Until recently the detection of carriers of mutations in hereditary cancer genes was aimed almost exclusively to the detection of subjects-at-risk, and consequently, personalized monitoring and preventive actions. However, it was revealed several years ago that some hereditary cancers are characterized by unique biological features and, therefore, unusual spectrum of drug sensitivity. For example, BRCA1/2-associated cancers usually demonstrate somatic loss of the remaining gene allele, and, hence, tumor-specific defects of DNA repair of double-strand breaks. This mechanism determines increased sensitivity of BRCA1/2-related cancers to cisplatin, mitomycin C and PARP inhibitors. Cancers arising as a part of Lynch syndrome can be effectively treated by the modulators of immune response. Tumors in patients with tuberous sclerosis often regress after administration of mTOR inhibitors. For the time being, there is already about a dozen of drugs demonstrating specific activity towards certain categories of hereditary cancers.
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PMID:[Specific features of drug sensitivity of hereditary cancers]. 3045 11

Ovarian epithelial cancer (OEC) is the most lethal gynecologic malignancy. Despite current chemotherapeutic and surgical options, this high lethality can be attributed to multiple factors, including late-stage presentation. In order to optimize OEC treatment, it is important to highlight that it is composed of five main subtypes: high-grade serous ovarian carcinoma (HGSOC), low-grade serous ovarian carcinoma (LGSOC), endometrioid ovarian carcinoma (EOC), ovarian clear cell carcinoma (CCOC), and mucinous ovarian carcinoma (MOC). These subtypes differ in their precursor lesions, as well as in epidemiological, morphological, molecular and clinical features. OEC is one of the tumours in which most pathogenic germline mutations have been identified. Accordingly, up to 20% OC show alterations in BRCA1/2 genes, and also, although with a lower frequency, in other low penetrance genes associated with homologous recombination deficiency (HRD), mismatch repair genes (Lynch syndrome) and TP53. The most important prognostic factor is the 2014 FIGO staging, while older age is also associated with worse survival. HGSOC in all stages and CCC and MOC in advanced stages have the worse prognosis among histological types. Molecular markers have emerged as prognostic factors, particularly mutations in BRCA1/2, which are associated with a better outcome. Regarding treatment, whereas a proportion of HGSOC is sensible to platinum-based treatment and PARP inhibitors due to HRD, the rest of the histological types are relatively chemoresistant. New treatments based in specific molecular alterations are being tested in different histological types. In addition, immunotherapy could be an option, especially for EOC carrying mismatch repair deficiency or POLE mutations.
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PMID:Morphological and molecular heterogeneity of epithelial ovarian cancer: Therapeutic implications. 3324 Apr 38

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