Why do cancer cells kill their hosts while when the host dies, they also die?

Creating cancer cells is a very complex process, requiring the coordination of many factors and the accumulation of many mutations to eventually form cancer.

Cancer cells are actually normal cells in our body but have undergone some changes that cause them to lose their normal function and control. Under normal conditions, the cells will divide. divide and die in an orderly manner according to the instructions of genes and health. However, sometimes errors occur in a cell's genes, these errors are called mutations , causing the cell's properties and functions to change.

Most mutations are harmless and some are even beneficial to cell adaptation and evolution. However, some mutations can cause cells to become harmful, and these mutations cause cancer. Under normal circumstances, most cells are "renewed" after a few days or months. Why do cells have to go through this complicated process to replace old cells and look like new cells?

Cancer cells are actually normal cells in our body.

We need to understand an important concept - the cell cycle . The cell cycle refers to the series of stages in which cells progress from birth to division and death. Regulation of the cell cycle is important to maintain the normal function of tissues and organs. Through orderly cell division and death, the body can regenerate and repair damaged tissues while maintaining a balanced cell population. If cells lose control of their cell cycle, it can lead to abnormal proliferation and tumor formation. 

Why can't cells live forever? This has to do with the life cycle of cells and the stability of genetic information. Every time a cell divides, the ends of chromosomes lose a small amount of DNA due to the special structure and function of telomeres. Telomeres are complexes of DNA and protein that exist at the ends of chromosomes , whose role is to protect chromosomes from damage and instability. As the number of cell divisions increases, telomeres will gradually shorten. When the length of telomeres reaches a certain level, the cell will enter a stage called 'clonal crisis'. 

During a clonal crisis, the cell's telomeres become too short to provide adequate protection. This leads to abnormal chromosome fusion and damage, triggering the cell's self-destruct mechanism. This self-destruct mechanism, called cellular "senescence" or "apoptosis" , ensures the destruction of damaged cells to avoid further growth of abnormal cells.

Telomeres are complexes of DNA and protein that exist at the ends of chromosomes.

However, not all cells die immediately after telomere decline. In some cases, cells can continue to divide, but these dividing cells carry damaged DNA with them. Over time, DNA damage in these cells accumulates, eventually leading to cell death or impaired function.

Normally, the body's immune system monitors and eliminates abnormal cells, including those with depleted telomeres. However, as lifespan increases and immune system function declines, individual abnormal cells can escape the control of the immune system and begin to divide uncontrollably.

The appearance of mutant cells is not significantly different from normal cells, this camouflage helps them avoid attacks by the immune system and survive in quiet corners. They will grow silently until they reach the early stages of tumor formation . At this point, even if the immune system detects them, it cannot effectively fight them and can only passively allow them to develop and grow. During this stage, these mutant cell populations will rob nutrients and surrounding space to meet their own growth needs. Therefore, tumors form.

Factors leading to cell cancer also have external causes.

Recent studies show that in addition to genetic mutations, factors leading to cell cancer also have external causes. In their study, the scientists found that the FOXR2 gene is normally turned off in normal human tissues, but is activated in at least 70% of cancers and 8% of individual tumors.

These findings were published in the International Journal of Cancer . When researchers compared the genetic sequences of childhood brain cancers, they were surprised to discover that many cancer patients had an abnormally active FOXR2 gene. Under normal circumstances, the FOXR2 gene is not expressed in any normal tissue except the testicles.

However, aberrant expression of FOXR2 has been found in many types of cancer, including bone cancer, melanoma and lung cancer. FOXR2 gene activity appears even in tumors. brain as diffuse midline glioma. Scientists believe that expression of the FOXR2 gene enhances the growth rate of brain tumors, including neuromas. Cells can activate the expression of this gene through a process called hypomethylation . When the FOXR2 gene is activated, a group of transcription factors called ETS are overexpressed, which can promote tumor formation. In other words, the FOXR2 gene is like an activation key that opens the door to cancer. When the FOXR2 gene becomes active, the process of cell cancer begins.

Most people's immune systems are effective at eliminating abnormal cells.

So the question is, are cancer cells only found in the patient's body? In fact, cell mutations can sometimes occur in the normal human body, leading to the appearance of cancer cells in the body. However, most people's immune systems effectively eliminate these abnormal cells, preventing them from developing into cancer.

Older people or people with poor health have a relatively high risk of cancer due to weakened immunity and weak ability to screen cancer cells. So why do cancer cells form tumors that endanger the host's life? Don't they know that once the host dies, they will also die? This is not the case, a study shows that most cells that become cancerous change during the aging process . During this period, cells have stopped dividing due to telomere deterioration and the body's immune system eliminates these cells.

Cells, like the human body, have a strong desire to survive. Driven by the instinctive desire to survive, those few cells begin to proliferate and mutate indefinitely, eventually forming cancer cells. Although they know very well that if this situation continues, the host they rely on for survival will soon die, and their entire population will be wiped out immediately, but these cells have been cloned. ability to dominate and cannot stop the division . This is the same as humans and the Earth, a few people control the resources and rights, because of their desire for enjoyment and selfish desires, they have continuously exploited the Earth's resources and destroyed the environment. Earth's field. Do they know that these actions are equivalent to destroying the Earth and ruining the future of humanity, but will they stop them?