The most important questions in cancer research and clinical oncology series: questions 15–24
drive cell division and differentiation. Sun Yat-sen University Cancer Center, Obesity-related cancers: more questions than answers. . External link. What is the relationship between interphase and cell division? .. Therefore, the relationship between stem cells and cancer cells needs to be more clearly. How DNA mutations during cell division cause cancer. Quick questions: at the end of most pages or sections there is a question or set of quick questions to.
EVs contain a variety of proteins such as transcription factors as well as nucleic acids such as DNA and non-coding regulatory RNAs 1, 2. Exosomes are originated from endocytic compartments 3relevantly reflecting the cytoplasmic content of their parent cells; microvesicles are shed directly from plasma membrane, comparatively reflecting the biology of cell surfaceome.
It is important to consider that the molecular content and the secreted levels of EVs are differentially reflected in each cancer type and grade, making EVs a potential source of cancer biomarkers 3, 4.
Extracellular vesicles act as conveners of intercellular communication by exchanging biological information between cells 5—7 and are largely implicated in determining cell fates 8. Based on their inherent capability of transferring regulatory elements, EVs may elicit a newly evolved mechanism of trans-regulation between cells and confer genomic instability in recipient cells 1.
The oncogenic content of EVs transferred from cancer cells to normal recipient cells could consequently induce malignant phenotypes 9— In a similar way, EVs could mediate an intercellular transfer of phosphatase and tensin homolog PTEN -targeting microRNAs to primary tumor cells in order to bypass tumor suppressor checkpoint and enable primary tumor cells to metastasize As such, the EV-mediated dissemination of bioactive content contributes to cell phenotypic transitions, immune modulation, and re-shaping of tumor microenvironment The most profound input of cancer-associated EVs is their participation in pre-metastatic niche formation by enabling cells to mobilize at new regions 14, As such, EVs from various tumor types forecast organ-specific metastasis organotropism by preferentially fusing at their predicted destinations in target organs through EV-linked distinct integrins Thus, EVs promote tumor organotropic metastasis and prepare favorable pre-metastatic niche for future metastasis.
Since cancer needs successful co-option with extracellular environment, tumor-derived EVs can condition tumor microenvironment for successful co-option of cancer cells in a given niche For this, EVs transport pro-angiogenic growth factors that cope with nutrient requirements in microenvironment and favor the formation of blood vessels 17or may undergo vessel co-option.
It is tempting to escalate that tumor cells have evolved yet another mean of co-option through suppressing anti-tumor immune cells by secreting EVs loaded with immune-suppressing ligands In fact, EVs carrying such ligands interact with corresponding receptors presented on immune cells and induce suppression or apoptosis of T cells and normal killer cells.
This mechanism facilitates cancer cells to co-exist in tumor microenvironment by suppressing anti-tumor immune cells Thus, given all observations together, EVs facilitate stochastic patterns of cancer physiology. Despite multifaceted roles of EVs in cancer biology, some important questions about their regulatory mechanisms and their clinical applications are yet to be answered.
On the biotech front, the answers to the above questions will improve the way of designing more precise therapeutic strategy for cancer patients. Collective efforts from academia and biotech industries are expected to translate EVs into a platform of innovative and personalized therapies.
What is the relationship between cancer cells and the cell cycle? | Socratic
References Fatima F, Nawaz M. Vesiculated long non-coding RNAs: Obstacles and opportunities in the functional analysis of extracellular vesicle RNA. The emerging role of extracellular vesicles as biomarkers for urogenital cancers.
They grow even when they are surrounded by other cells causing a mass to form. The behavior of normal top animation and cancer cells bottom animation with regard to contact inhibition is depicted below. The round containers in which the cells are depicted in the animations are called petri dishes.
In the laboratory, cells are often grown in these, covered with a nutrient-rich liquid. Cellular Senescence Most cells also seem to have a pre-programmed limit to the number of times that they can divide. Interestingly, the limit seems to be based, in part, on the cell's ability to maintain the integrity of its DNA. An enzyme, telomerase, is responsible for upkeep of the ends of the chromosomes.
What is the relationship between cancer cells and the cell cycle?
In adults, most of our cells don't utilize telomerase so they eventually die. In cancer cells, telomerase is often active and allows the cells to continue to divide indefinitely.
For more information on telomerase, see the Cancer Genes section Cancer Cell Division When it comes to cell division, cancer cells break just about all the rules!
Cancer cells can divide without appropriate external signals. This is analogous to a car moving without having pressure applied to the gas pedal.
Some breast cancer cells actually lose the ability to respond to estrogen by turning off expression of the receptor for estrogen within the cell. These cells can still reproduce by bypassing the need for the external growth signal. While most cells can tell if they are being 'crowded' by nearby cells, cancer cells no longer respond to this stop signal. As shown above, the continued growth leads to the piling up of the cells and the formation of a tumor mass.
Cancer cells can divide without receiving the 'all clear' signal. The results of this are 'daughter' cells that contain abnormal DNA or even abnormal numbers of chromosomes. These mutant cells are even more abnormal than the 'parent' cell. In this manner, cancer cells can evolve to become progressively more abnormal. Continued cell division leads to the formation of tumors.