[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-378277-105":59,"doc-detail-378277-en":131},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":124,"head_meta":126,"extra_data":128,"updated_unix":130},105,"en","methylation-of-brca1-promoter-in-sporadic-breast-cancer","Methylation of BRCA1 promoter in sporadic breast cancer","","Methylation of the BRCA1 promoter in sporadic breast cancer is discussed in the context of breast-cancer risk driven by hormonal and genetic factors. The commentary explains the role of estrogen in DNA damage, the need for reliable biomarkers, and how epigenetic alterations—including promoter hypermethylation and chromatin remodeling—contribute to early tumorigenesis. It summarizes BRCA1 functions, links promoter hypermethylation to reduced BRCA1 expression and protein loss, and outlines detection approaches such as quantitative PCR and bisulfite sequencing PCR, including methylation-specific multiplex ligation-dependent probe amplification.",{"@graph":69,"@context":123},[70,84,106],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/methylation-of-brca1-promoter-in-sporadic-breast-cancer/378277/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/methylation-of-brca1-promoter-in-sporadic-breast-cancer/378277.png","ImageObject",300,407,{"name":92,"@type":93},"Stanley","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-10-30","2026-09-24",true,{"@type":102,"interactionType":103,"userInteractionCount":105},"InteractionCounter",{"@type":104},"ViewAction",11,{"@type":107,"mainEntity":108},"FAQPage",[109,115,119],{"name":110,"@type":111,"acceptedAnswer":112},"Why is BRCA1 promoter methylation relevant to sporadic breast cancer?","Question",{"text":113,"@type":114},"Promoter hypermethylation can inactivate BRCA1, reducing gene copy number and downregulating BRCA1 expression and protein levels. This contributes to tumor development as an epigenetic silencing mechanism.","Answer",{"name":116,"@type":111,"acceptedAnswer":117},"Which techniques are mentioned for measuring promoter methylation and related expression?",{"text":118,"@type":114},"The text refers to quantitative PCR and bisulfite sequencing PCR to assess differences between BRCA1 mRNA expression and promoter methylation. It also mentions methylation-specific multiplex ligation-dependent probe amplification for detecting abnormal DNA methylation.",{"name":120,"@type":111,"acceptedAnswer":121},"How does promoter hypermethylation relate to gene silencing in cancer?",{"text":122,"@type":114},"Methylation within promoter regions of tumor-suppressor genes typically causes their silencing. The commentary presents promoter methylation as an alternative to mutation or allelic loss during cancer progression.","https://schema.org",{"og:url":83,"og:type":125,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":127,"canonical":83},"index,follow",{"doc_id":129,"site_id":62},378277,1790805011,{"code":4,"msg":5,"data":132},{"doc_id":129,"user_id":133,"nickname":92,"user_avatar":134,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":135,"file_id":136,"file_url":137,"file_type":138,"file_size":139,"view_count":105,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":81,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":39},2336477405376,"https://ap-avatar.wpscdn.com/davatar_29158cc5080c5b710cf443261637dec0","Indian J Med Res 158, July 2023, pp 85-87 DOI: 10.4103/ijmr.ijmr_ 1574_22  \nCommentary  \nMethylation ofBRCA1 promoter in sporadic breast cancer  \n\n| Quick Response Code: |\n| --- |\n| |\n\nThe major risk for the development of breast cancer is related to hormonal and genetic factor1. The germline mutation is mostly responsible for hereditary breast carcinomas while hormonal factors for sporadic breast carcinomas (SBCs) . Oestrogen plays an important role in breast tumour development due to its direct carcinogenetic effect and is also responsible for cellular DNA damage and mutations.  \nBreast cancer is the most commonly diagnosed malignancy worldwide2 and a leading causes of cancer death among women3. In clinical practice, early diagnosis of breast cancer has a significant role. Currently, various techniques are employed for abreast lump evaluation including sonomammography, fine needle aspiration cytology (FNAC), core biopsy, xeroradiography, thermography, frozen sections, hormonal study, immunohistochemistry (IHC) and molecular diagnosis. For the early detection of breast cancer and its disease progression, there is a requirement of a reliable biomarker.  \nVarious genetic and epigenetic changes in tumour suppressor genes and oncogenes are thought to be responsible for the development of breast cancer. To detect and target such epigenetic changes, various diagnostic methods are required which will be helpful to treat and prevent breast cancers.  \nTwo such breast cancer susceptibility genes are noted by linkage studies, the breast cancer gene 1 (BRCA1) located on chromosome 17g12-21 and BRCA2 , located on 13q12-13 . The BRCA1 is a multifunctional protein involved in DNA repair, control of cell cycle checkpoints, protein ubiquitination and chromatin remodelling. Any changes or mutations in this gene can lead to an increased risk of developing breast, ovarian or prostate cancer. It is a classic tumour suppressor gene that plays a significant role in hereditary breast cancers. It is observed that BRCA1 gene mutation  \nis commonly associated with familial hereditary breast cancer, however, it is rarely found in SBC4 . Also reported frequency of BRCA1 gene mutation is relatively less in men.  \nAbout 5-10 per cent of cases of hereditary breast cancer are due to BRCA1 or BRCA2 germline mutations. It is responsible for 40-80 per cent lifetime risk of developing breast cancer5. With a history of familial BRCA1 or BRCA2 gene mutation, there are reportedly 50 per cent chances of having the same gene mutation6. The reported incidence is about one in every 500 women in the United States with a mutation in either her BRCA1 or BRCA2 gene.  \nInactivation of BRCA1 by promoter hypermethylation is associated with reduced gene copy number and chromosome 17 aneusomy6. There is decreased expression of BRCA1 gene as well as protein in breast cancer as compared to normal mammary epithelial cells. In about 19 per cent of SBCs, both nuclear and cytoplasmic BRCA1 protein loss has been observed7.  \nA biomarker for the diagnosis of breast cancer is to study the differences in DNA methylation pattern. The differences between BRCA 1 mRNA expression and promoter methylation are done by quantitative PCRand bisulfite sequencing PCR technics. Methylation within the promoter regions of tumour-suppressor genes typically causes their silencing8. It is observed that the multiple factors are involved in the initiation and progression of breast tumours.  \nThe epigenetic alterations of the genome such as DNA promoter methylation and chromatin remodelling play an important role in the early phase of tumourigenesis. The promoter methylation assays serve as pre-screening tests and have been widely employed for breast cancer detection, prognosis as well as in treatment.  \n© 2023 Indian Journal of Medical Research, published by Wolters Kluwer-Medknow for Director-General, Indian Council of Medical Research  \n86 INDIAN J MED RES, JULY 2023  \nMethylation-specific multiplex ligat","cbCair6RUmpAyI2u","https://ap.wps.com/l/cbCair6RUmpAyI2u","pdf",490265,"English","# Commentary\n## Breast cancer risk and need for biomarkers\n## Genetic and epigenetic mechanisms in tumor development\n## BRCA1 promoter hypermethylation and gene silencing\n## Detection methods for promoter methylation and diagnosis\n## Clinical associations and study context","[{\"question\":\"Why is BRCA1 promoter methylation relevant to sporadic breast cancer?\",\"answer\":\"Promoter hypermethylation can inactivate BRCA1, reducing gene copy number and downregulating BRCA1 expression and protein levels. This contributes to tumor development as an epigenetic silencing mechanism.\"},{\"question\":\"Which techniques are mentioned for measuring promoter methylation and related expression?\",\"answer\":\"The text refers to quantitative PCR and bisulfite sequencing PCR to assess differences between BRCA1 mRNA expression and promoter methylation. It also mentions methylation-specific multiplex ligation-dependent probe amplification for detecting abnormal DNA methylation.\"},{\"question\":\"How does promoter hypermethylation relate to gene silencing in cancer?\",\"answer\":\"Methylation within promoter regions of tumor-suppressor genes typically causes their silencing. The commentary presents promoter methylation as an alternative to mutation or allelic loss during cancer progression.\"}]","Methylation of BRCA1 promoter in sporadic breast cancer | PDF",1790229307]