Civil Rights
Movements, leaders, victories and the continuing fight for equality.
q2K BHP
Black History Portal
THE BHP WIRE —
HIDDEN TRUTHS
What's New!
Explore the people, places, events, achievements, struggles and stories that shaped our journey.
Movements, leaders, victories and the continuing fight for equality.
Innovation, patents, science, technology and world-changing contributions.
Pioneers, champions, Negro Leagues, records, activism and excellence.
Meet the people whose lives, choices and achievements shaped the journey.
Black towns, communities, institutions and places where history happened.
Moments that changed communities, movements, institutions and the nation.
Katherine Johnson’s mathematical calculations helped guide some of America’s most important early space missions while she confronted the racial and gender barriers faced by Black women in twentieth-century America.
MORE →Reflects the personal views, recollections, and perspective of the author, Mike Davis.
This is a personal recollection on the Move fire on May 13, 1985
RAD51 homolog C (S. cerevisiae), also known as RAD51C, is a protein which in humans is encoded by the RAD51C gene.[5][6]
The RAD51C protein is one of five paralogs of RAD51, including RAD51B (RAD51L1), RAD51C (RAD51L2), RAD51D (RAD51L3), XRCC2 and XRCC3. They each share about 25% amino acid sequence identity with RAD51 and each other.[7]
The RAD51 paralogs are all required for efficient DNA double-strand break repair by homologous recombination and depletion of any paralog results in significant decreases in homologous recombination frequency.[8]
RAD51C forms two distinct complexes with other related paralogs: BCDX2 (RAD51B-RAD51C-RAD51D-XRCC2) and CX3 (RAD51C-XRCC3). These two complexes act at two different stages of homologous recombinational DNA repair. The BCDX2 complex is responsible for RAD51 recruitment or stabilization at damage sites.[8] The BCDX2 complex appears to act by facilitating the assembly or stability of the RAD51 nucleoprotein filament.
The CX3 complex acts downstream of RAD51 recruitment to damage sites.[8] The CX3 complex was shown to associate with Holliday junction resolvase activity, probably in a role of stabilizing gene conversion tracts.[8]
The RAD51C gene of rice has an essential role in meiosis in both male and female gametocytes.[9] RAD51C is also required for repair of DNA damage in rice somatic cells.[9]
The RAD51C gene is one of genes four localized to a region of chromosome 17q23 where amplification occurs frequently in breast tumors. Overexpression of the four genes during amplification has been observed and suggests a possible role in tumor progression. Alternative splicing has been observed for this gene and two variants encoding different isoforms have been identified.[5]
A characteristic of many cancer cells is that parts of some genes contained within these cells have been recombined with other genes. One such gene fusion that has been identified in a MCF-7 breast cancer cell line is a chimera between the RAD51C and ATXN7 genes.[10][11] Since the RAD51C protein is involved in repairing double strand chromosome breaks, this chromosomal rearrangement could be responsible for the other rearrangements.[11]
RAD51C mutation increases the risk for breast and ovarian cancer, and was first established as a human cancer susceptibility gene in 2010.[12][13][14] Carriers of an RAD51C mutation had a 5.2-fold increased risk of ovarian cancer, indicating that RAD51C is a moderate ovarian cancer susceptibility gene.[15] A pathogenic mutation of RAD51C was present in approximately 1% to 3% of unselected ovarian cancers, and among mutation carriers, the lifetime risk of ovarian cancer was approximately 10-15%.[16][17][18][19]
In addition, there are three other causes of RAD51C deficiency that also appear to increase cancer risk. These are alternative splicing, promoter methylation and repression by over-expression of EZH2.
Three alternatively spliced RAD51C transcripts were identified in colorectal cancers. Variant 1 is joined from the 3' end of exon-6 to the 5' end of exon-8, variant 2 is joined at the 3' end of exon-5 to the 5' end of exon-8, and variant 3 is joined from the 3' end of exon-6 to the 5' end of exon-9.[20] Presence and mRNA expression of variant 1 RAD51C was found in 47% of colorectal cancers. Variant 1 mRNA was expressed about 5-fold more frequently in colorectal tumors than in non-tumor tissues, and when present, was expressed 8-fold more frequently than wild-type RAD51C mRNA. The authors concluded that variant 1 mRNA was associated with the malignant phenotype of colorectal cancers[20]
In the case of gastric cancer, reduced expression of RAD51C was found in about 40% to 50% of tumors, and almost all tumors with reduced RAD51C expression had methylation of the RAD51C promoter.[21] On the other hand, methylation of the RAD51C promoter was only found in about 1.5% of ovarian cancer cases.[17]
EZH2 protein is up-regulated in numerous cancers.[22][23] EZH2 mRNA is up-regulated, on average, 7.5-fold in breast cancer, and between 40% and 75% of breast cancers have over-expressed EZH2 protein.[24] EZH2 is the catalytic subunit of polycomb repressive complex 2 (PRC2) which catalyzes methylation of histone H3 at lysine 27 (H3K27me) and mediates epigenetic gene silencing of target genes via local chromatin reorganization.[23] EZH2 targets RAD51C, reducing RAD51C mRNA and protein expression (and also represses other RAD51 paralogs RAD51B, RAD51D, XRCC2 and XRCC3).[25] Increased expression of EZH2, leading to repression of RAD51 paralogs and consequent reduced homologous recombinational repair, was proposed as a cause of breast cancer.[26]
RAD51C has been shown to interact with:
Source: Wikipedia. Article content is retrieved live through the MediaWiki API.
RAD51 homolog C (S. cerevisiae), also known as RAD51C, is a protein which in humans is encoded by the RAD51C gene.
Saruparib is an investigational new drug that is being evaluated for the treatment of cancer. It first-in-class selective inhibitor of poly-ADP ribose polymerase 1 (PARP1), designed to treat cancers with homologous recombination repair (HRR) deficiencies as a result of mutations in BRCA1, BRCA2, PALB2, RAD51C, or RAD51D genes.
Rice is a cereal grain and, in its domesticated form, is the staple food of over half of the world's population, particularly in Africa and Asia. Rice is the seed of the grass species Oryza sativa (Asian rice)—or, less commonly, Oryza glaberrima (African rice). Asian rice was domesticated in China some 13,500 to 8,200 years ago; African rice was domesticated independently in West Africa about 3,000 years ago. Rice has become commonplace in many cultures worldwide; in 2023, 800 million tons were produced, placing it third after sugarcane and maize. Only some 8% of rice is traded internationally. China, India, and Indonesia are the largest consumers of rice. A substantial amount of the rice produced in developing nations is lost after harvest through factors such as poor transport and storage. Rice yields can be reduced by pests including insects, rodents, and birds, as well as by weeds, and by diseases such as rice blast. Traditional rice polycultures such as rice-duck farming, and modern integrated pest management seek to control damage from pests in a sustainable way. Dry rice grain is milled to remove the outer layers; depending on how much is removed, products range from brown rice to rice with germ and white rice. Some is parboiled to make it easy to cook. Rice contains no gluten; it provides protein but not all the essential amino acids needed for good health. Rice of different types is eaten around the world. The composition of starch components within the grain, amylose and amylopectin, gives it different texture properties. Long-grain rice, from the Indica cultivar, tends to stay intact on cooking, and is dry and fluffy. The aromatic rice varieties, such as basmati and jasmine, are widely used in Asian cooking, and distinguished by their bold and nutty flavor profile. Medium-grain rice, from either the Japonica or Indica cultivar, or a hybrid of both, is moist and tender and tends to stick together. Its varieties include Calrose, which founded the Californian rice industry, Carnaroli, attributed as the king of Italian rice due to its excellent cooking properties, and black rice, which looks dark purple due to high levels of anthocyanins, and is also known as forbidden rice as it was reserved for the consumption of the royal family in ancient China. Short-grain rice, primarily from the Japonica cultivar, has an oval appearance and sticky texture. It is featured heavily in Japanese cooking such as sushi (with rice such as Koshihikari, Hatsushimo, and Sasanishiki, unique to different regions of climate and geography in Japan), as it keeps its shape when cooked. It is also used for sweet dishes such as mochi (with glutinous rice), and in European cuisine such as risotto (with arborio rice) and paella (with bomba rice, which is actually an Indica variety). Cooked white rice contains 29% carbohydrate and 2% protein, with some manganese. Golden rice is a variety produced by genetic engineering to contain vitamin A. Production of rice is estimated to have caused over 1% of global greenhouse gas emissions in 2022. Predictions of how rice yields will be affected by climate change vary across geographies and socioeconomic contexts. In human culture, rice plays a role in various religions and traditions, such as in weddings.
Ovarian cancer is a cancerous tumor of an ovary. It may originate from the ovary itself or more commonly from nearby structures such as fallopian tubes or the inner lining of the abdomen. The ovary is made up of three different cell types including epithelial cells, germ cells, and stromal cells. When these cells become abnormal, they can divide and form tumors. These cells can also invade or metastasize (spread) to other parts of the body. When this process begins, there may be no or only vague symptoms. Symptoms become more noticeable as the cancer progresses. These symptoms may include bloating, vaginal bleeding, pelvic pain, abdominal swelling, constipation, and loss of appetite, among others. Common areas to which the cancer may spread include the lining of the abdomen, lymph nodes, lungs, and liver. The risk of ovarian cancer increases with age. Most cases of ovarian cancer develop after menopause. It is also more common in women who have ovulated more over their lifetime. This includes those who have never had children, those who began ovulation at a younger age and those who reach menopause at an older age. Other risk factors include hormone therapy after menopause, fertility medication, and obesity. Factors that decrease risk include hormonal birth control, tubal ligation, pregnancy, and breast feeding. About 10% of cases are related to inherited genetic risk; women with mutations in the genes BRCA1 or BRCA2 have about a 50% chance of developing the disease. Some family cancer syndromes, such as hereditary nonpolyposis colon cancer and Peutz-Jeghers syndrome, also increase the risk of developing ovarian cancer. Epithelial ovarian cancer is the most common type of ovarian cancer, comprising more than 90% of cases. There are five main subtypes of ovarian carcinoma, of which high-grade serous carcinoma (HGSC) is the most common. Less common types of ovarian cancer include germ cell tumors and sex cord stromal tumors. A diagnosis of ovarian cancer is confirmed through a biopsy of tissue, usually removed during surgery. Screening is not recommended in women who are at average risk, as evidence does not support a reduction in death and the high rate of false positive tests may lead to unneeded surgery, which is accompanied by its own risks. Those at very high risk may have their ovaries removed as a preventive measure. If caught and treated in an early stage, ovarian cancer is often curable. Treatment usually includes some combination of surgery, radiation therapy, and chemotherapy. Outcomes depend on the extent of the disease, the subtype of cancer present, and other medical conditions. The overall five-year survival rate in the United States is 52%. Outcomes are worse in the developing world. In 2020, new cases occurred in approximately 313,000 women. In 2019 it resulted in 13,445 deaths in the United States. Death from ovarian cancer increased globally between 1990 and 2017 by 84.2%. Ovarian cancer is the second-most common gynecologic cancer in the United States. It causes more deaths than any other cancer of the female reproductive system. Among women, it ranks fifth in cancer-related deaths. The typical age of diagnosis is 63. Death from ovarian cancer is more common in North America and Europe than in Africa and Asia. In the United States, it is more common in White and Hispanic women than Black or American Indian women.
Before the 1921 destruction of Tulsa’s Greenwood District, Black residents had created a remarkable center of business and community life. The district included stores, professional offices, entertainment venues and homes owned by Black citizens. Understanding Greenwood means learning what was built—not only what was burned.
MORE →Shirley Chisholm, elected in 1968.
