Question

What are the three basic cellular pathways that cancer disrupts?

Short answer

The three basic cellular pathways that cancer disrupts are cell division or proliferation, programmed cell death or apoptosis, and cell differentiation. This disruption leads to uncontrolled growth and division of cells, avoidance of cell death, and production of immature and non-functional cells respectively.

Step-by-step solution

Understanding Cell Division/Proliferation

Cell division or proliferation is the process by which a cell divides into two daughter cells via the stages of the cell cycle (interphase, mitosis, and cytokinesis). In normal cells, cell division is carefully regulated. However, cancer disrupts this regulation leading to uncontrolled cell growth and division. This disruption can happen due to mutation in genes regulating cell cycle like oncogenes and tumor suppressor genes.

Understanding Programmed Cell Death/Apoptosis

Programmed cell death or apoptosis is a genetically controlled process of cell self-destruction to maintain cell populations in tissues and to eliminate cells that threaten an organism's survival. When this process is corrupted, as it is in cancer, cells that should die continue to divide and grow forming a tumor.

Understanding Cell Differentiation

Cell differentiation is the process by which generic cells change into specific cells meant to do certain tasks within the body. This process is disrupted in cancer, leading to cells that are immature and do not function properly within their intended role. Instead, these cells continue to divide and contribute to the growth of the tumor.

Key concepts

Cell Division

Cell division is a fundamental process required for growth, development, and repair in all organisms. It involves the duplication of a cell's genetic material and its division into two daughter cells. Under normal circumstances, this process is highly controlled and involves several crucial stages like interphase, mitosis, and cytokinesis.
In the context of cancer, this control is lost. Instead of dividing only when needed, cancer cells divide uncontrollably due to mutations in key regulatory genes such as oncogenes and tumor suppressor genes. This leads to the mass proliferation of cells that can give rise to tumors. These cells ignore the body’s normal checks and balances, behaving selfishly rather than contributing to the body’s health and functionality.

• Interphase: Cells grow and prepare for division.
• Mitosis: Chromosomes are divided between two new cells.
• Cytokinesis: Final division into two separate cells.

A disruption in this carefully orchestrated process is one hallmark of cancer development.

Apoptosis

Apoptosis, or programmed cell death, is the body's method of removing unnecessary or damaged cells, keeping our tissues healthy and working correctly. It’s a sort of cellular clean-up operation where cells meticulously "plan" their own demise for the greater good of the organism.
When you think about cancer, imagine a glitch in this clean-up process. Cancerous cells often avoid apoptosis by altering pathways and structures that would typically trigger cell death. This means cells that should be eliminated manage to survive, continue to divide, and eventually form tumors. Imagine overrun factories churning out unneeded products, clogging up the system. In essence, without proper apoptosis, there is unchecked cellular debris, living on past their expiry date, contributing to cancer's malignant potential.

Cell Differentiation

Cell differentiation is how unspecialized cells develop into specific cell types with distinct functions, akin to how a child learns to become proficient in a particular career. Each differentiated cell serves a purpose, from carrying oxygen as a red blood cell to sending signals as a nerve cell.
In cancer, this development process goes awry. Tumor cells typically become less differentiated—their traits become more primitive. These immature cells don't perform the specific tasks they should in their given tissue. Instead, they proliferate without fulfilling their roles, contributing to an inefficient and overcrowded environment.

• Normal differentiation leads to functional, mature cells.
• Loss of differentiation in cancer results in dysfunctional, immature cells.
• These cells continue to divide without undertaking their intended functions.

Through the disruption of differentiation, cancer undermines the delicately balanced systems our body relies upon.