Cancer Cell Biology: A General Overview of Factors Linked to Cancer Development and Its Progression

By: Ariana Gopal

Cancer forms when a cell veers away from its normal pattern of cell division and begins to proliferate abnormally.  This proliferation can lead to the development of a mass of cells known as a tumor.  This high proliferation of abnormal cells can eventually damage nearby tissues or enter the bloodstream or the lymph system and begin to damage tissues further away (known as cancer metastases).  This continued replication of abnormal cells can negatively impact the functioning of the tissues targeted by the cancer, which is why it can be so deadly.  (NIH, 2007)

Overtime, researchers have proposed numerous theories regarding what causes the development cancer.  One of of these theories was that specific cancers can be induced by specific environmental conditions.  For example, in the 1770s, there was a high correlation between working as a chimney sweeper as a child and developing scrotal cancer later on in life (NIH, 2007).  Even today, we see an extensive correlation between cigarette smoking and lung cancer.

Although these environmental factors do put people at increased risk for developing cancer, a number of researchers have been taking a biological approach toward understanding various cancers’ origins.  Cancer systems biology is geared toward analyzing how cellular networks in normal cells are disrupted to eventually develop into cancer cells (Werner, 2014).  It does not disregard environmental factors, but its primary focus is how a person’s replicating cells are disrupted on a biological level in order to yield cancer.   In fact, these environmental conditions may essentially result in the genomic abnormalities that lead to the development of cancerous cells.

As a result of the linkage between biological abnormalities and the development of cancer, physicians and researchers have proposed cellular and genetic research toward characterizing the underlying mechanisms of certain cancers.  One way of doing this is considered the “single cell approach” (Doxie & Irish, 2014).  By evaluating cancer cells this way, researchers have the capability of identifying complex, abnormal phenotypical characteristics of cancer cells and evaluating whether or not the genetic mutation or abnormal signaling pathways present in the cells are specific to a single cell subset or exist across all cancer cells (Doxie & Irish, 2014).  Having this knowledge can essentially help researchers develop more effective treatment methods for targeting various forms of cancer and treating patients.

Systems biology has indicated that a wide range of mutational differences exist across various cancers.  For example, neuroblastoma, prostate cancer, as well as breast cancers have a fewer number of genetic mutations prominent in the abnormal cells opposed to those in lung cancers and cancers related to sun exposure (Gentles & Gallahan, 2011).  These higher genetic alterations can be indicative that carcinogenic environmental factors play a significant role in increasing genomic mutations that lead to the development cancer.  In addition to general genomic mutations, impaired DNA repair pathways have been deemed prominent across various cancers (Gentles & Gallahan, 2011).

In addition to looking at individual cells and genetic pathways, researchers have also focused directly on the progression of tumor development.  One article specifically discussed the idea that tissue cells are typically exposed to physical stressors, such as pressure and tension (Butcher et al., 2009).  The cells that make up these tissues are forced to respond to these external stressors by reciprocating the force they are being exposed to (Butcher et al., 2009). This article ultimately suggests that losing the ability to return the stress placed on tissue cells can actually lead to the progression of malignant tumors for cancer patients (Butcher et al., 2009).

Overall, the articles presented in this paper shed light on what doctors and scientists know about cancer.  They suggest that genetic mutations and altered signaling pathways, which can be influenced by environmental factors, lead to the development of cancer, and that evaluating cancer from a biological perspective can increase people’s understandings of what exactly causes cancer. From evaluating tissue cells, researchers can also better understand factors that lead to the progression of malignant tumors.

Figure 1: The process of tumor development and metastasis (NIH, 2007). As cancerous cells begin to replicate and form malignant tumors, cells can break off from the tumor and travel into the bloodstream. This means that the cancer has become delocalized and will effect more organs, thus making it harder to treat.  

References

Butcher, Darci T., Tamara Alliston, and Valerie M. Weaver. “A Tense Situation: Forcing Tumour Progression.” Nature Reviews Cancer 9.2 (2009): 108-22.

Doxie, Deon B., and Jonathan M. Irish. “High-Dimensional Single-Cell Cancer Biology.” Current Topics in Microbiology Immunology (2014): 1-21.

Gentles, Andrew J., and Daniel Gallahan. “Meeting Report: “Systems Biology: Confronting the Complexity of Cancer”.” Cancer Research 71.18 (2011): 5961-964. Web.

National Institutes of Heath. “Understanding Cancer.” National Institutes of Heath (2007)

Werner, Henrica M.J., Gordon B. Mills, and Prahlad T. Ram. “Cancer Systems Biology: A Peak into the Future of Patient Care?” Nature Reviews Clinical Oncology (2014): 167-76.