The Process of Mitosis and Cancer Development
Cancer refers to a range of diseases that involve the development and proliferation of abnormal cells. This illness is closely related to the process of mitosis, and more specifically to the errors occurring during this process. Generally, mitosis is only one stage of the cell cycle, during which a cell divides into two identical cells (Simon, Dickey, & Reece, 2019). Prior to mitosis, a cell goes through three more phases.
During the G1 phase, a cell has the chromosome that it received during the previous division (McIntosh, 2016). Then, the S phase follows, during which the DNA is replicated (McIntosh, 2016). The following G2 phase is characterized by the presence of sister chromatids that are tied together with cohesins (McIntosh, 2016). Then, mitosis takes place, which is a very complicated and important process since it determines whether the newly formed cells will be normal.
The primary difficulty during mitosis is to divide the duplicated DNA of a cell accurately. The fact is that the length of the DNA is far greater than the diameter of a cell (McIntosh, 2016). Therefore, to fit into a cell, the DNA is condensed, and then, the mitotic spindle separates the formed chromosomes and moves them to the opposite poles (McIntosh, 2016). Generally, cells are divided accurately, and each newly formed cell receives the right number of chromosomes.
However, mistakes during mitosis happen sometimes, which results in a too large or too small number of chromosomes in daughter cells, and it is called aneuploidy (Levine & Holland, 2018). Aneuploidy is a common attribute of cancer tumors, alongside other structural changes in chromosomes, such as “deletions, amplifications, and translocations” (Levine & Holland, 2018, p. 620). The wrong segregation of chromosomes during mitosis leads to the formation of cells with the damaged DNA, which have genome instability and lead to the formation of more abnormal cells (Levine & Holland, 2018).
Furthermore, mitotic defects can cause tumors, for example, if formed cells lack the chromosome containing a tumor suppressor gene (Levine & Holland, 2018). Thus, cancer develops as a result of errors occurring during the process of mitosis.
Causes and Treatment of Hepatocellular Carcinoma
The article under consideration is devoted to the causes and treatment of hepatocellular carcinoma (HCC). This disease is also called malignant hepatoma, and it is “the sixth most common cancer” that has high death rates (Dutta & Mahato, 2017, p. 106). HCC is “the cancer of liver parenchymal cells,” which is difficult to treat (Dutta & Mahato, 2017, p. 107). The authors list the causes for this type of cancer, which include chronic hepatitis B and C, chronic consumption of alcohol, obesity, liver cirrhosis, type 2 diabetes, NAFLD, and metabolic disorders (Dutta & Mahato, 2017).
The treatment often involves surgical resection, but it is suitable only for patients at the early stage of liver cancer, and their “survival rate reaches 70 % if the tumor is < 2” (Dutta & Mahato, 2017). Hence, early diagnosis of this disease has a crucial significance for a patient’s chances for recovery.
After exploring the causes of HCC, the authors review currently available treatment options for this disease and suggest the use of nanomedicines. One treatment option is chemotherapy using sorafenib that is the only approved drug for treating this type of cancer (Dutta & Mahato, 2017). However, chemotherapy has many side effects, including toxicity, the development of drug resistance, and the emergence of other cancers (Dutta & Mahato, 2017). Other treatment options are monoclonal antibody therapy, Interferon-based therapy, targeting peptides, and miRNA-based therapies (Dutta & Mahato, 2017).
The authors suggest that the use of nanomedicines could become an effective alternative to chemotherapy and surgery (Dutta & Mahato, 2017). The advantage of nanomedicines is that they can deliver medications to the sites where they are necessary. They can reach tumors through the leaky vasculature, thus delivering drugs to the damaged cells and minimizing side effects for other organs (Dutta & Mahato, 2017). This treatment option is still under development, but it offers hope for possible alternatives for curing liver cancer.
Written Transcript
Body cells are constantly dividing, and sometimes, this process goes with some errors. As a result, newly formed cells may receive the wrong number of chromosomes, and their DNA is damaged. If there are many such cells in the body, it may cause cancer. Liver cancer is one of the deadliest types of cancer, and it is seldom treated with drugs. According to Dutta and Mahato (2017), nowadays, the most frequent treatment option for liver cancer is surgery, but it can hardly help people in the late stage of the disease. Scientists continue their efforts to find an effective cure for cancer.
Recently, researchers have started to look toward nanomedicine that may suggest alternative solutions to cancer treatment. Dutta and Mahato (2017) explain that with the help of nanomedicines, medics will be able to deliver drugs exactly to the damaged organs or tissues, and this will improve their efficiency and reduce their side effects. The researchers argue that the new way of drug delivery to cancer tumors is a promising approach to successful treatment of liver cancer (Dutta & Mahato, 2017). However, this method is still under development and requires thorough research before it can be widely implemented in practice. Dutta and Mahato’s research was funded by the National Institutes of Health and the University of Nebraska Medical Center.
References
Dutta, R., & Mahato, R. I. (2017). Recent advances in hepatocellular carcinoma therapy. Pharmacology & Therapeutics, 173, 106-117.
Levine, M. S., & Holland, A. J. (2018). The impact of mitotic errors on cell proliferation and tumorigenesis. Genes and Development, 32(9-10), 620-638.
McIntosh, J. R. (2016). Mitosis. Cold Spring Harbor Perspectives in Biology, 8(9), 1-16.
Simon, E. J., Dickey, J. L., & Reece, J. B. (2019). Campbell essential biology (7th ed.). New York, NY: Pearson.