The basics of molecular biology and its relationship with lung cancer

The basics of molecular biology and its relationship with lung cancer

According to class IB1005.1 "Fundamentals of biological systems" cancer is a disorder at the cellular level, where an overproduction of cells is generated during its life cycle. When there is an unnecessary amount of cells, the body of the organism begins to work in a way that it is not supposed to (ACS, 2016). According to Knowles and Selby 2005, cancer is a cell disorder that is usually seen as a tumor made up of a bunch of cells. However, the visible tumor is the last stage of a series of changes that took several years to develop.

Cancer has no physical cure, that is, this disorder is directly related to the genetic material and habits of each individual, so a remedy such as a drug or pill is impossible to invent, at least for the near future.

In the cell cycle, the cell in question goes through the interface to synthesize a replication of it and finally through a mitosis to complete the separation. Throughout this process, there are various control points at the interface, as in the G1 and G2 sub-stages, in which the procreation of mutated cells is avoided. In this way, the correct functioning of the body's cell production is ensured.

In the presence of a damaged cell, proteins like Rb, P53 and P21 are capable of inducing mutated cells into cell arrest (also known as G0) and wait for a reparation. In the event that an arrangement does not occur, the damaged cell continues with its apoptosis, or programmed death. It also prevents it from reaching the stage of mitosis.

In most cases, cancer originates when there is a failure in these barriers (proteins such as Rb, P53 and P21) and causes a generation of mutated cells. About 50% of cases reside when the P53 protein, known as "the genome guardian", suffers a mutation itself and, therefore, is unable to filter cells with erroneous genetic content and command them to apoptosis. It also leads to uncontrolled production of these cells that, in turn, damages the body's genetic material. (Openstax Biology, 2016)

However, for cases of lung cancer, the misfortune in the cell cycle is not everything. Take as an example a carcinogen such as a cigar. Inhaled smoke will pass through the trachea of ​​the individual. In continuous use, cigar chemicals will react with the tracheal epithelium causing a change in the organ phenotype, also known as a metaplasia. Then the origin of the cancer is promoted in situ in that area of ​​the body that can lead to dysplasia, where it is unable to reverse the damage caused.

Pneumocytes are a type of cells present in the pulmonary alveoli and are divided into two categories: type I and type II.

Type I pneumocytes occupy 95% of the alveolar surface and are responsible for coating the membrane of the alveolar sac to increase its exposure to gas exchange. Type II pneumocytes occupy the remaining 5% of the alveolar surface and their function is to produce the pulmonary surfactant. The surfactant is a lipoprotein complex capable of reducing surface tension within the alveoli, preventing a collapse between them when exhaling. Finally, the NCI describes macrophages as a type of white blood cell responsible for destroying microorganisms and inciting the production of other immune cells.

A cell contains the genetic material (DNA) of an organism, which is used for unicellular and multicellular functions. In addition, it is where the energy of each individual is obtained, generating adenosine triphosphate through a process called “cellular respiration”. Proteins are chains of amino acids that have a specific function in the body and are created inside one of the organelles of the cell, the ribosomes.

According to the video “Cycles of Matter and Energy Transfer” by Bozeman Science, it is denoted as the transfer of energy is a cyclical process where it is determined that humans are categorized as type II or type III consumers. The presenter, Paul Andersen, comments how humans subsist on the energy of producers (plants) and consumers of type I (animals). In addition, Paul points out how it all starts with the ability of plants to generate glucose through the process of photosynthesis and how that energy is transferred to other types of organisms. Through food, humans get the energy to carry out their daily activities

What race or ethnicity is more likely to develop lung cancer? Taking tobacco use as an example, visualizing it from a social perspective, the statistics present an insignificant variance between the percentage increases in the use of tobacco in different races or ethnicities, so the answer to our question lies in another area.

The black race has a higher incidence rate of lung and bronchi cancer compared to the white race. Likewise, the mortality rate is also higher. By dividing by gender, it is concluded that black men are 51 percent more likely to develop these types of cancer compared to white men. While the signs of black and white women present a similarity to each other. The reason is that black women are commonly diagnosed with this condition before white women. (Pfizer, 2005)

According to Higgins, Lewis, Warren 2003, it is generally accepted that early surgery of lung cancer can be curative and is the best method to preserve survival. Unfortunately, trends throughout history place African Americans as less likely to receive hospital service to treat small cell carcinoma. This topic is no longer just about scientific fields since the socioeconomic area is also included.

To recap, the reasons for such a high disparity between ethnic groups and races are not completely clear. Researchers have examined the behavior of tobacco use, occupational exposure, genetics, access to health systems, discrimination, among other contributors. The answer appears to be a set of interactions of biological, environmental, political and cultural factors (Hicks, 2010)

References:

• (n.d.). Dictionary of cancer. Retrieved from https://www.cancer.gov/espanol/publicaciones/dictionary/def/macrofago

• Carrero, I., & Herraez, Á. (n.d.). The world of lipids. Retrieved from http://biomodel.uah.es/model2/lip/surfac-lung.htm

• Hanahan, D., & Weinberg, R. A. (2011). Hallmarks of Cancer: The Next Generation. Cell, 144 (5), 646–674.doi: 10.1016 / j.cell. 2011.02.013

• Clark, M. A., Douglas, M., & Choi, J. (2018). Chapter 10 - Cell Reproduction. In OpenStax Biology (2nd ed.).

• (2019, February 20). Tobacco Use in Racial and Ethnic Populations. Retrieved from https://www.lung.org/stop-smoking/smoking-facts/tobacco-use-racial-and-ethnic.html

• Higgins, R. S.., Lewis, C., & Warren, W. H. (2003). Lung cancer in african americans. The Annals of Thoracic Surgery, 76 (4), S1363 – S1366.doi: 10.1016 / s0003-4975 (03) 01208-6

• Pfizer (Ed.). (2005). Racial Differences in Cancer. Retrieved from https://www.pfizer.com/sites/default/files/products/Racial_Differences_in_Cancer.pdf

• Hicks, W. (2010). Too Many Cases, Too Many Deaths: Lung Cancer in African Americans. Retrieved from https://www.lung.org/assets/documents/research/ala-lung-cancer-in-african.pdf

• LS2B - Cycles of Matter and Energy Transfer. (2013). Retrieved from https://www.youtube.com/watch?v=x37DJLcJ0dI