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Introduction to Cells, DNA, and Viruses
Published in Patricia G. Melloy, Viruses and Society, 2023
Cellular macromolecules are organized into compartments called organelles (like little organs) that have an organization allowing for the work of the cell to happen. So, like organs such as the heart and lungs that have a special role in the body, organelles have a special role inside the cell. Some examples of key cellular organelles include the nucleus (where DNA is housed), mitochondria (energy generation), and ribosomes (protein production). Except for the nucleolus residing in the nucleus, organelles are found in what is known as the cytoplasm or cytosol of the eukaryotic cell. The nucleus is an important organelle because it acts as the central control point for all the activities of the cell. The nucleus houses most of the cell’s DNA in the form of protein/DNA structures known as chromosomes that allow for condensation of the large amount of genetic material in each cell (Alberts et al. 2019). Cell division occurs in a process known as mitosis, in which the chromosomes are copied and separated equally between the two daughter cells. Later, we will talk about organelles that help move or traffic things around the cell, as well as into and out of the cell. Trafficking-related organelles include the endoplasmic reticulum, Golgi apparatus, and vesicles. Viruses can exploit the cellular trafficking network to move into and out of the cell.
Introduction to Cancer
Published in David E. Thurston, Ilona Pysz, Chemistry and Pharmacology of Anticancer Drugs, 2021
Cell division is a physiological process that occurs in almost all tissues and under many circumstances. Under normal circumstances, the balance between proliferation and programmed cell death (usually mediated by apoptosis) is maintained by tightly regulating both processes to ensure the integrity of organs and tissues. It is now accepted that cancer is a genetic disease resulting from changes to DNA sequence information in one or more genes, or from more profound structural changes such as chromosomal translocations.
The Fight Against Cancer
Published in Nathan Keighley, Miraculous Medicines and the Chemistry of Drug Design, 2020
The daughter cells, produced after cell division, will now have the correct genetic information for controlling cellular processes. There are two forms of cell division: mitosis and meiosis. Mitosis produces two daughter cells and enables cells to replicate for growth and repair. Meiosis produces four daughter cells, each with half the number of chromosomes: haploid cells, which are important for making gametes, which fuse during fertilisation to make diploid cells, and ultimately a foetus.
Toxicity of Persian Gulf shell-less marine mollusc (Peronia peronii) methanolic extract on melanoma tumor mitochondria
Published in Cutaneous and Ocular Toxicology, 2023
Yalda Arast, Aida Jabbarzadeh, Farahnaz Tanbakosazan, Abdollah Arjmand, Amir. Vazirizadeh, Jalal Pourahmad
In advanced countries, cancer is one of the most important causes of death. Cell division happens regularly in tissues as part of a normal cell cycle. To have normal tissue is necessary to strike a precise balance between the two main process of proliferation and apoptosis [1,2]. The mortality rate is dramatically expanded, even though the frequency of malignant Melanoma is minor than %0.8 per 100 000 people. In fact, over the past 60 years, the overall mortality rate from MM in China has risen steadily at a 6.5% annual rate. The most lethal skin cancer, Melanoma, relies heavily on the acute activity of mitochondria and ROS for its persistence. Recent studies have shown that healthy tissue has consistent mitochondrial morphology, tissue, and protein expression, whereas this pattern is not seen in skin cancer [3,4]. Due to the vast oceans that cover two-thirds of the planet, the dominant ecosystem on the Earth is the marine ecosystem, which is home to about half of biodiversity [5]. In compounds extracted from marine origins, bioactive properties with various activities have been observed, such as anti-tumour, anti-cancer, anti-microtubule, anti-proliferative, anti-hypertensive, cytotoxic, and antibiotic properties. These substances have a variety of chemical properties, including phenol, alkaloids, terpenoids, polyesters, and other secondary metabolites present in sponges, bacteria, dinoflagellate, and seaweed [6–8].
Inhibitors of cell cycle checkpoint target Wee1 kinase – a patent review (2003–2022)
Published in Expert Opinion on Therapeutic Patents, 2022
Jingxue Yan, Lili Zhuang, Yong Wang, Yiqing Jiang, Zhenlin Tu, Chao Dong, Yadong Chen, Yong Zhu
Cancer characterized with uncontrolled cell proliferation caused by dysregulation of cell cycle is a main cause of death, surpassing cardiovascular disease in some countries. The proper conduct of the cell cycle depends on the strict control of cell cycle checkpoints. Cell cycle checkpoints ensure the detection mechanism for DNA replication and chromosome assignment during the cell cycle. Checkpoints provide more time for DNA repair prior to replication, genome replication, and regulation of mitosis by delaying the progression of the cell cycle. Diminished or lost checkpoint function leads to decreased efficiency of DNA replication to increase and induce gene mutations and chromosomal aberrations. There are two key processes in eukaryotic mitosis, namely DNA synthesis (G1-S phase), and the balanced distribution of sister chromatids into the two daughter cells (G2-M phase), where Wee1 kinase plays an important role in the latter by jointly regulating the phosphorylation of CDC2 with cell division cyclin 25 (CDC25).
MOS mutation causes female infertility with large polar body oocytes
Published in Gynecological Endocrinology, 2022
Guangzhong Jiao, Huayu Lian, Jinhao Xing, Lili Chen, Zhaoli Du, Xiaoyan Liu
Proper oocyte maturation is essential for subsequent fertilization and early embryonic development, which is necessary for successful reproduction [1]. We can evaluate the morphology of human oocytes with the help of assisted reproductive technology [2]. Maturation of oocytes requires two meiosis. During meiosis, bipolar meiotic spindles form and homologous chromosomes are arranged through microtubule-organizing centers (MTOCs) [3–5]. After the spindle is assembled, with the extrusion of the first polar body, the oocyte extrudes half of its genetic material and then goes directly into the metaphase II (MII); the oocyte arrests at MII until fertilization [6, 7]. Unlike the symmetric cell division that occurs in mitosis, mammalian oocyte meiosis is characterized by asymmetric division, producing a highly polarized and large metaphase II-arrested oocyte and a small polar body [8]. The failure of asymmetric oocyte division results in the production of large polar bodies in oocytes, usually due to low oocyte quality or aging after ovulation [9]. In mice, some studies have identified abnormal gene expression leading to a meiotic spindle dysfunction phenotype; however, the genetic etiology of human oocytes remains largely unknown.