The key difference between contact inhibition and metastasis is that contact inhibition is a property of normal cells that involves the prevention of uncontrolled proliferation of cells when they are in contact with other neighbouring cells while, metastasis is a property of tumour that involves the rapid growth of tumour cells, invasion of neighbouring tissues and reaching distant sites of the body through blood and lymph.
Cell proliferation is an increase in the number of cells in the body as a result of cell growth and cell division. Cell proliferation requires both cell growth and cell division to happen at the same time. In multicellular organisms, cell proliferation is controlled by gene regulatory networks. Uncontrolled cell proliferation leads to an increased proliferation rate and causes cancers. Contact inhibition is a well-known property of a normal cell, while metastasis is a property of a tumour cell.
CONTENTS
1. Overview and Key Difference
2. What is Contact Inhibition
3. What is Metastasis
4. Similarities Between Contact Inhibition and Metastasis
5. Side by Side Comparison – Contact Inhibition vs Metastasis in Tabular Form
6. Summary
What is Contact Inhibition?
Contact inhibition is a well-known property of normal cells. It’s a mechanism that prevents the uncontrolled proliferation of cells when they are in contact with other neighbouring cells. Contact inhibition has two phenomena: contact inhibition of locomotion (CIL) and contact inhibition of proliferation (CIP). Contact inhibition of locomotion refers to the avoidance of motile behaviour exhibited by cells like fibroblast when they are in contact with one another. When the collision is unavoidable, a different phenomenon, the contact inhibition of proliferation occurs, where the cell growth itself is eventually stopped in a cell density-dependent manner.
Contact inhibition contributes to the regulation of proper tissue growth, differentiation, and development. Both types of regulations in the contact inhibition are well-negated normally during organogenesis, embryonic development and tissue and wound healing. Contact inhibition is aberrantly absent in the cancer cells. This absence of regulation leads to tumorigenesis.
What is Metastasis?
Metastasis refers to the spread of cancer cells from the place where they first formed to another part of the body. Cancer cells grow rapidly, invade the neighbouring tissues and are capable of reaching distant sites of the body through blood and lymph. When this happens, it is said cancer has “metastasized” Bloodstream or lymphatic system carry fluid throughout the body. It means that the cancer cell can travel very far from the original location and form new tumours once they settle.
Figure 01: Metastasis
Metastasis can also happen when tumours in the belly or abdominal cavity break off and grow in nearby tissues such as the liver, lungs or bones. Cancers can spread to every part of the body. For example, breast cancer tends to spread to the bone, liver, brain, lungs and chest wall. Lung cancer tends to spread to the brain, bones, liver and adrenal glands. Prostate cancer can spread to bones. Furthermore, colon cancer can spread to the lungs and liver. But less frequently, cancer can spread to the skin, muscle or any other part of the body. Metastasis can be treated through systematic therapies such as chemotherapy, hormone therapy or immune therapy. It can also be treated with radiation therapy and surgeries.
What are the Similarities Between Contact Inhibition and Metastasis?
- Contact inhibition and metastasis are connected to cell proliferation.
- Both are regulated by genes networks.
- These phenomena involve cell contacts with other neighbouring cells.
What is the Difference Between Contact Inhibition and Metastasis?
Contact inhibition involves the prevention of uncontrolled proliferation of cells when they are in contact with other neighbouring cells. In contrast, metastasis involves the rapid growth of tumour cells, invasion of neighbouring tissues and reaching distant sites of the body through blood and lymph. So, this is the key difference between contact inhibition and metastasis. Moreover, contact inhibition is a property of normal cells. In contrast, metastasis is a property of cancer cells.
The following infographic shows the differences between contact inhibition and metastasis in tabular form.
Summary – Contact Inhibition vs Metastasis
Cell proliferation is a process that results in an increase in the number of cells. It is the right balance between cell division and cell loss. Cell proliferation is increased in an uncontrollable way in cancers. Contact inhibition of proliferation is the phenomenon where cells stop proliferating upon contact. It is a property of normal cells. However, metastasis is a phenomenon where cancer cells spread from the original site to another part of the body. Thus, this is the summary of the difference between contact inhibition and metastasis.
Reference:
1. “Contact Inhibition.” An Overview | ScienceDirect Topics, Available here.
2. “What Is Metastasis?” Cancer.Net, 5 Dec. 2019, Available here.
Image Courtesy:
1. “Metastasis sites for common cancers-IT” By Jemal A, Siegel R, Ward E et al. (2008) Cancer statistics, 2008, 58, pp. 71–96 DOI: 10.3322/CA.2007.0010. (CC0) via Commons Wikimedia